Everything Solar Forum

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu
------------------------------

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

Hi,

I live in New England and have a 7kW solar array on my roof. For the past week we have had snow on our panels continuously due to the low daytime temps which prevented snow melt during the day. It has been so frustrating on a beautiful cool sunny day seeing no to little solar energy being produced due to the covered panels! Meanwhile we are receiving emails from the micro-inverter manufacturer stating that our system is not producing as much energy as expected. No kidding!

Regards,
John Lynch

------------------------------
John Lynch
jlynchcc@gmail.com
------------------------------

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

Hi John - I feel your pain!  Similar conditions here in northeast Ohio, but we've had some days where temps are near freezing and it's possible, with the right tools, to restore some lost kilowatts.  See photo...

------------------------------
Mike Curran
joacchim57@gmail.com
------------------------------

Original Message:
Sent: Feb 19, 2021 09:18 AM
From: John Lynch
Subject: Solar and Snow

Hi,

I live in New England and have a 7kW solar array on my roof. For the past week we have had snow on our panels continuously due to the low daytime temps which prevented snow melt during the day. It has been so frustrating on a beautiful cool sunny day seeing no to little solar energy being produced due to the covered panels! Meanwhile we are receiving emails from the micro-inverter manufacturer stating that our system is not producing as much energy as expected. No kidding!

Regards,
John Lynch

------------------------------
John Lynch
jlynchcc@gmail.com

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

try to get a grip and put in perspective   a whole week of no output is only 2%   and given that its a typical weak winter week of short days cloudy wx and extra shading its even less

best advice is to ignore it unless its extremely easy and safe to remove

------------------------------
Drew Gillett
p.e.
Solar Engineers
deaneg@hotmail.com
------------------------------

Original Message:
Sent: Feb 19, 2021 09:18 AM
From: John Lynch
Subject: Solar and Snow

Hi,

I live in New England and have a 7kW solar array on my roof. For the past week we have had snow on our panels continuously due to the low daytime temps which prevented snow melt during the day. It has been so frustrating on a beautiful cool sunny day seeing no to little solar energy being produced due to the covered panels! Meanwhile we are receiving emails from the micro-inverter manufacturer stating that our system is not producing as much energy as expected. No kidding!

Regards,
John Lynch

------------------------------
John Lynch
jlynchcc@gmail.com

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

To look only at the "issue" from a percentage perspective of total production is a bit narrow. You can make a case for that perspective if the ROI is the ONLY thing you care about. Winter time as you noted has reduced production. Often the sunny days that you do get are following a snow storm. That may be the only clear day you get for two, three or four days. Having your panels sit there mostly inactive can result in a very low production month VS clearing them when a PSD (Perfect Solar Day) presents itself. These "bursts" of energy into grid-out production or storage can be like the water hole trekking through the desert. 
This point is brought into focus particularly for off girders.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Feb 22, 2021 05:08 PM
From: Drew Gillett
Subject: Solar and Snow

try to get a grip and put in perspective   a whole week of no output is only 2%   and given that its a typical weak winter week of short days cloudy wx and extra shading its even less

best advice is to ignore it unless its extremely easy and safe to remove

------------------------------
Drew Gillett
p.e.
Solar Engineers
deaneg@hotmail.com

Original Message:
Sent: Feb 19, 2021 09:18 AM
From: John Lynch
Subject: Solar and Snow

Hi,

I live in New England and have a 7kW solar array on my roof. For the past week we have had snow on our panels continuously due to the low daytime temps which prevented snow melt during the day. It has been so frustrating on a beautiful cool sunny day seeing no to little solar energy being produced due to the covered panels! Meanwhile we are receiving emails from the micro-inverter manufacturer stating that our system is not producing as much energy as expected. No kidding!

Regards,
John Lynch

------------------------------
John Lynch
jlynchcc@gmail.com

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

Original Message:
Sent: 2/23/2021 12:02:00 AM
From: william fitch
Subject: RE: Solar and Snow

To look only at the "issue" from a percentage perspective of total production is a bit narrow. You can make a case for that perspective if the ROI is the ONLY thing you care about. Winter time as you noted has reduced production. Often the sunny days that you do get are following a snow storm. That may be the only clear day you get for two, three or four days. Having your panels sit there mostly inactive can result in a very low production month VS clearing them when a PSD (Perfect Solar Day) presents itself. These "bursts" of energy into grid-out production or storage can be like the water hole trekking through the desert. 
This point is brought into focus particularly for off girders.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Feb 22, 2021 05:08 PM
From: Drew Gillett
Subject: Solar and Snow

try to get a grip and put in perspective   a whole week of no output is only 2%   and given that its a typical weak winter week of short days cloudy wx and extra shading its even less

best advice is to ignore it unless its extremely easy and safe to remove

------------------------------
Drew Gillett
p.e.
Solar Engineers
deaneg@hotmail.com

Original Message:
Sent: Feb 19, 2021 09:18 AM
From: John Lynch
Subject: Solar and Snow

Hi,

I live in New England and have a 7kW solar array on my roof. For the past week we have had snow on our panels continuously due to the low daytime temps which prevented snow melt during the day. It has been so frustrating on a beautiful cool sunny day seeing no to little solar energy being produced due to the covered panels! Meanwhile we are receiving emails from the micro-inverter manufacturer stating that our system is not producing as much energy as expected. No kidding!

Regards,
John Lynch

------------------------------
John Lynch
jlynchcc@gmail.com

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

I am grid tie with trackers, so snow rarely collects on my PV. My solar thermal I broom after each storm if needed.
As far as Red Herring's, I can't say I find the term "Red Herring" meaningful when you are getting more of something good, regarding the initial purchase or the clearing of snow.
As far as yearly production numbers, though not really relevant to this conversation, last year I set a new yearly production record of 19.375 MWH's. If you are interested in more numbers, you will find them on my Website's home page, on the left and down a bit.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Feb 23, 2021 05:39 AM
From: Drew Gillett
Subject: Solar and Snow

no numbers in ur reply to work with

ill bet 95% plus of solar systems r on grid

which r u ?

id agree that in very limited circumstances its worth the trouble like if u r on a no production tarif or have storage or ur grid needs help (tx) or have ur net priduction trued up in dec  like here in fl ( oh thats right no snow in my net pos winter home 3000kwh  ) or in my net pos summer home in nh where net prod another 3000 kwh is banked forever  in both cases a second ev would help

in essence snow is an engineering red herring

most should safely ignore it

Sent from my iPhone

Original Message:
Sent: 2/23/2021 12:02:00 AM
From: william fitch
Subject: RE: Solar and Snow

To look only at the "issue" from a percentage perspective of total production is a bit narrow. You can make a case for that perspective if the ROI is the ONLY thing you care about. Winter time as you noted has reduced production. Often the sunny days that you do get are following a snow storm. That may be the only clear day you get for two, three or four days. Having your panels sit there mostly inactive can result in a very low production month VS clearing them when a PSD (Perfect Solar Day) presents itself. These "bursts" of energy into grid-out production or storage can be like the water hole trekking through the desert. 
This point is brought into focus particularly for off girders.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Feb 22, 2021 05:08 PM
From: Drew Gillett
Subject: Solar and Snow

try to get a grip and put in perspective   a whole week of no output is only 2%   and given that its a typical weak winter week of short days cloudy wx and extra shading its even less

best advice is to ignore it unless its extremely easy and safe to remove

------------------------------
Drew Gillett
p.e.
Solar Engineers
deaneg@hotmail.com

Original Message:
Sent: Feb 19, 2021 09:18 AM
From: John Lynch
Subject: Solar and Snow

Hi,

I live in New England and have a 7kW solar array on my roof. For the past week we have had snow on our panels continuously due to the low daytime temps which prevented snow melt during the day. It has been so frustrating on a beautiful cool sunny day seeing no to little solar energy being produced due to the covered panels! Meanwhile we are receiving emails from the micro-inverter manufacturer stating that our system is not producing as much energy as expected. No kidding!

Regards,
John Lynch

------------------------------
John Lynch
jlynchcc@gmail.com

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

Original Message:
Sent: 2/23/2021 8:48:00 AM
From: william fitch
Subject: RE: Solar and Snow

I am grid tie with trackers, so snow rarely collects on my PV. My solar thermal I broom after each storm if needed.
As far as Red Herring's, I can't say I find the term "Red Herring" meaningful when you are getting more of something good, regarding the initial purchase or the clearing of snow.
As far as yearly production numbers, though not really relevant to this conversation, last year I set a new yearly production record of 19.375 MWH's. If you are interested in more numbers, you will find them on my Website's home page, on the left and down a bit.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Feb 23, 2021 05:39 AM
From: Drew Gillett
Subject: Solar and Snow

no numbers in ur reply to work with

ill bet 95% plus of solar systems r on grid

which r u ?

id agree that in very limited circumstances its worth the trouble like if u r on a no production tarif or have storage or ur grid needs help (tx) or have ur net priduction trued up in dec  like here in fl ( oh thats right no snow in my net pos winter home 3000kwh  ) or in my net pos summer home in nh where net prod another 3000 kwh is banked forever  in both cases a second ev would help

in essence snow is an engineering red herring

most should safely ignore it

Sent from my iPhone

Original Message:
Sent: 2/23/2021 12:02:00 AM
From: william fitch
Subject: RE: Solar and Snow

To look only at the "issue" from a percentage perspective of total production is a bit narrow. You can make a case for that perspective if the ROI is the ONLY thing you care about. Winter time as you noted has reduced production. Often the sunny days that you do get are following a snow storm. That may be the only clear day you get for two, three or four days. Having your panels sit there mostly inactive can result in a very low production month VS clearing them when a PSD (Perfect Solar Day) presents itself. These "bursts" of energy into grid-out production or storage can be like the water hole trekking through the desert. 
This point is brought into focus particularly for off girders.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Feb 22, 2021 05:08 PM
From: Drew Gillett
Subject: Solar and Snow

try to get a grip and put in perspective   a whole week of no output is only 2%   and given that its a typical weak winter week of short days cloudy wx and extra shading its even less

best advice is to ignore it unless its extremely easy and safe to remove

------------------------------
Drew Gillett
p.e.
Solar Engineers
deaneg@hotmail.com

Original Message:
Sent: Feb 19, 2021 09:18 AM
From: John Lynch
Subject: Solar and Snow

Hi,

I live in New England and have a 7kW solar array on my roof. For the past week we have had snow on our panels continuously due to the low daytime temps which prevented snow melt during the day. It has been so frustrating on a beautiful cool sunny day seeing no to little solar energy being produced due to the covered panels! Meanwhile we are receiving emails from the micro-inverter manufacturer stating that our system is not producing as much energy as expected. No kidding!

Regards,
John Lynch

------------------------------
John Lynch
jlynchcc@gmail.com

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

Yes Tom!
That is exactly what I was thinking of.  I was up in my ladder but the uppermost panels are not areas that I can reach with my broom and a pole, also concerned about scratching the surface when plopping the broom down on the glass.

Whoever might invent such a thing would be a boon to young and old alike!

Selena

------------------------------
Selena Lucas
slucasdvm@gmail.com
------------------------------

Original Message:
Sent: Feb 24, 2021 10:10 AM
From: Tom Wilson
Subject: Solar and Snow

Hi Drew! Long time...

I've always thought a reasonable solution to the snow pile-up-up issues would be to embed basic electrical resistance coils into the panels themselves, and then when sensors record that the panels are covered in snow that it would send a moderate electrical charge either from battery back-up or the grid into those coils...right at the surface that would enable the snow to slide off of the panels. Experimentation would reveal if some sort of smart sequence would be necessary...when to start the heating, do you start at the bottom and work up,?? I don't know, but it seems to me that the overall energy balance would be positive.

Has anybody tried this? Is there product on the market?

Tom Wilson???

Citizens Climate Lobby Vermont State Coordinator???

Warren, VT

715 829 3512???

??

HOME REMEDIES Residential Energy Services

707 Railroad Ave???

Viroqua, WI 54665??????

715 829 3512???

resenergy@mwt.net??????

??

???Action is the antidote to despair????? ??? Joan Baez

Original Message:
Sent: 2/23/2021 8:48:00 AM
From: william fitch
Subject: RE: Solar and Snow

I am grid tie with trackers, so snow rarely collects on my PV. My solar thermal I broom after each storm if needed.
As far as Red Herring's, I can't say I find the term "Red Herring" meaningful when you are getting more of something good, regarding the initial purchase or the clearing of snow.
As far as yearly production numbers, though not really relevant to this conversation, last year I set a new yearly production record of 19.375 MWH's. If you are interested in more numbers, you will find them on my Website's home page, on the left and down a bit.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Feb 23, 2021 05:39 AM
From: Drew Gillett
Subject: Solar and Snow

no numbers in ur reply to work with

ill bet 95% plus of solar systems r on grid

which r u ?

id agree that in very limited circumstances its worth the trouble like if u r on a no production tarif or have storage or ur grid needs help (tx) or have ur net priduction trued up in dec  like here in fl ( oh thats right no snow in my net pos winter home 3000kwh  ) or in my net pos summer home in nh where net prod another 3000 kwh is banked forever  in both cases a second ev would help

in essence snow is an engineering red herring

most should safely ignore it

Sent from my iPhone

Original Message:
Sent: 2/23/2021 12:02:00 AM
From: william fitch
Subject: RE: Solar and Snow

To look only at the "issue" from a percentage perspective of total production is a bit narrow. You can make a case for that perspective if the ROI is the ONLY thing you care about. Winter time as you noted has reduced production. Often the sunny days that you do get are following a snow storm. That may be the only clear day you get for two, three or four days. Having your panels sit there mostly inactive can result in a very low production month VS clearing them when a PSD (Perfect Solar Day) presents itself. These "bursts" of energy into grid-out production or storage can be like the water hole trekking through the desert. 
This point is brought into focus particularly for off girders.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Feb 22, 2021 05:08 PM
From: Drew Gillett
Subject: Solar and Snow

try to get a grip and put in perspective   a whole week of no output is only 2%   and given that its a typical weak winter week of short days cloudy wx and extra shading its even less

best advice is to ignore it unless its extremely easy and safe to remove

------------------------------
Drew Gillett
p.e.
Solar Engineers
deaneg@hotmail.com

Original Message:
Sent: Feb 19, 2021 09:18 AM
From: John Lynch
Subject: Solar and Snow

Hi,

I live in New England and have a 7kW solar array on my roof. For the past week we have had snow on our panels continuously due to the low daytime temps which prevented snow melt during the day. It has been so frustrating on a beautiful cool sunny day seeing no to little solar energy being produced due to the covered panels! Meanwhile we are receiving emails from the micro-inverter manufacturer stating that our system is not producing as much energy as expected. No kidding!

Regards,
John Lynch

------------------------------
John Lynch
jlynchcc@gmail.com

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

Question about snow removal from panels: is there a heating device made that can assist snow melt from PV panels?

------------------------------
Selena Lucas
slucasdvm@gmail.com
------------------------------

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

I don't think so, but it's been my observation that if you can get some portion of your panels cleared of snow, the sun plus the heating effect of current flow through the panels will do the rest.

------------------------------
Mike Curran
Retired from (dare I say it?) Fossil Plant Mgt.
joacchim57@gmail.com
------------------------------

Original Message:
Sent: Feb 22, 2021 08:38 AM
From: Selena Lucas
Subject: Solar and Snow

Question about snow removal from panels: is there a heating device made that can assist snow melt from PV panels?

------------------------------
Selena Lucas
slucasdvm@gmail.com

Original Message:
Sent: Feb 18, 2021 08:47 PM
From: Robert Foster
Subject: Solar and Snow

Hi Luis,

PV modules are durable and reliable and snow does not cause any harm to solar panels.

PV actually performs better in the cold (less voltage drop) and can exceed their power rating; we design PV systems (Voc) for the coldest day of the year since that is when voltage will be highest.

Solar panels as part of their qualification to meet IEC 61215 / UL1703 already go thru thermal stress torture cycle testing from cold to hot in a short timeframe; this is used to stress solder bond joints.

Also PV is tested for hail stone strikes (something like ~1 inch hail stone at 60 mph).

Snow load tests are also performed usually from 2,400 to 5,400 Pa.

The only problem with snow is that obviously little or no sunlight is shining module so they cannot produce power if covered with snow. 

In some snowy regions like Siberia, N. China, or Alaska, bi-facial PV modules take advantage of thereflected sunlight from the snow underneath to produce power on both sides of the PV module.


------------------------------
Robert Foster
Assistant Professor
New Mexico State University
Las Cruces NM
rfoster@nmsu.edu

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

No Harm. Get a long handled broom with extension if you don't want to let the sun do it.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

We don't get much snow in the Middle Rio Grande Valley but we had 4 days last week where I got my daily exercise brooming them clean. "Chop your own wood and it will warm you twice"

A 3' length of 1" PVC pipe with a coupler popped onto the end of my Craftsman push broom which had a bit of electrical tape on the end to get the pipe to fit tightly extended the reach of the broom to match the collectors. A friend commented how his single axis tracking collectors - the utility scale solar standard - was just a flip to vertical to dump all the snow in a flash.

------------------------------
Andrew Stone
CEO
PACE Fund NM
andrew@stone.com
------------------------------

Original Message:
Sent: Feb 19, 2021 10:40 AM
From: william fitch
Subject: Solar and Snow

No Harm. Get a long handled broom with extension if you don't want to let the sun do it.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

We use an 16' extendable pool brush to push off the snow.  Works pretty well

------------------------------
Brad Klafehn
Retired
brad@bradk.org
------------------------------

Original Message:
Sent: Feb 24, 2021 10:34 AM
From: Andrew Stone
Subject: Solar and Snow

We don't get much snow in the Middle Rio Grande Valley but we had 4 days last week where I got my daily exercise brooming them clean. "Chop your own wood and it will warm you twice"

A 3' length of 1" PVC pipe with a coupler popped onto the end of my Craftsman push broom which had a bit of electrical tape on the end to get the pipe to fit tightly extended the reach of the broom to match the collectors. A friend commented how his single axis tracking collectors - the utility scale solar standard - was just a flip to vertical to dump all the snow in a flash.

------------------------------
Andrew Stone
CEO
PACE Fund NM
andrew@stone.com

Original Message:
Sent: Feb 19, 2021 10:40 AM
From: william fitch
Subject: Solar and Snow

No Harm. Get a long handled broom with extension if you don't want to let the sun do it.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

I use a roof rake, specifically made for removing snow from a roof, attached to a long PVC pipe. No climbing on ladders! After most of the snow is removed, the sun does the rest.

------------------------------
David Arnosti
Haslett Community Church - Green Team; and Board Member, Michigan Interfaith Power and Light
arnosti@msu.edu
------------------------------

Original Message:
Sent: Feb 25, 2021 10:16 AM
From: Brad Klafehn
Subject: Solar and Snow

We use an 16' extendable pool brush to push off the snow.  Works pretty well

------------------------------
Brad Klafehn
Retired
brad@bradk.org

Original Message:
Sent: Feb 24, 2021 10:34 AM
From: Andrew Stone
Subject: Solar and Snow

We don't get much snow in the Middle Rio Grande Valley but we had 4 days last week where I got my daily exercise brooming them clean. "Chop your own wood and it will warm you twice"

A 3' length of 1" PVC pipe with a coupler popped onto the end of my Craftsman push broom which had a bit of electrical tape on the end to get the pipe to fit tightly extended the reach of the broom to match the collectors. A friend commented how his single axis tracking collectors - the utility scale solar standard - was just a flip to vertical to dump all the snow in a flash.

------------------------------
Andrew Stone
CEO
PACE Fund NM
andrew@stone.com

Original Message:
Sent: Feb 19, 2021 10:40 AM
From: william fitch
Subject: Solar and Snow

No Harm. Get a long handled broom with extension if you don't want to let the sun do it.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

I've never used one of these but they've always intrigued me.
Avalanche-Worlds Best Snow Rake

YouTube		remove preview
Avalanche-Worlds Best Snow Rake Easy to use tool for roof snow removal. View this on YouTube >

------------------------------
Mike Curran
Retired from (dare I say it?) Fossil Plant Mgt.
joacchim57@gmail.com
------------------------------

Original Message:
Sent: Feb 26, 2021 09:15 AM
From: David Arnosti
Subject: Solar and Snow

I use a roof rake, specifically made for removing snow from a roof, attached to a long PVC pipe. No climbing on ladders! After most of the snow is removed, the sun does the rest.

------------------------------
David Arnosti
Haslett Community Church - Green Team; and Board Member, Michigan Interfaith Power and Light
arnosti@msu.edu

Original Message:
Sent: Feb 25, 2021 10:16 AM
From: Brad Klafehn
Subject: Solar and Snow

We use an 16' extendable pool brush to push off the snow.  Works pretty well

------------------------------
Brad Klafehn
Retired
brad@bradk.org

Original Message:
Sent: Feb 24, 2021 10:34 AM
From: Andrew Stone
Subject: Solar and Snow

We don't get much snow in the Middle Rio Grande Valley but we had 4 days last week where I got my daily exercise brooming them clean. "Chop your own wood and it will warm you twice"

A 3' length of 1" PVC pipe with a coupler popped onto the end of my Craftsman push broom which had a bit of electrical tape on the end to get the pipe to fit tightly extended the reach of the broom to match the collectors. A friend commented how his single axis tracking collectors - the utility scale solar standard - was just a flip to vertical to dump all the snow in a flash.

------------------------------
Andrew Stone
CEO
PACE Fund NM
andrew@stone.com

Original Message:
Sent: Feb 19, 2021 10:40 AM
From: william fitch
Subject: Solar and Snow

No Harm. Get a long handled broom with extension if you don't want to let the sun do it.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------

As indicated in my recent post for another subject, my ground mounted, two high, retiltable panels are at a 65° angle in the winter and easily cleaned with a squejee on a standard handle if the snow doesn't just slide off. Just another example of the advantage of ground mounting if space permits.

------------------------------
Phillip Geil
Retired Professor
phgeil@gmail.com
------------------------------

Original Message:
Sent: Feb 18, 2021 12:03 PM
From: Luis Ramon
Subject: Solar and Snow

The crazy temperature this week has brought to the United States has me thinking if snow could damage solar panels or does snow act as rain. What I mean by this is that whenever snow falls (like this week) does snow damage the panel? Example Texas, where they don't expect any snow are the panels prepared to be "hit" by the snow or do all the panels have a response as they do for the rain.

------------------------------
Luis Ramon
lura1075@colorado.edu
------------------------------