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David Hrivnak

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RE: current PV install cost per watt ?

Posted By David Hrivnak 06-23-2023 11:15 AM
Found In Egroup: Everything Solar Forum \ view thread
There are many variables, size of system, ease of working on the roof..... We are a small time installer and typically will see as low as $2.25/watt on a large job with easy access to $3.30/watt for smaller installs on a challenging roof. There is a certain amount of fixed costs that small 4-6kW systems ...

RE: Solar powered factories making hemp batteries and the future is hemp buildings?

Posted By David Hrivnak 04-08-2023 02:35 PM
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As for a Hemp battery and EV's I think the proponents have been smoking too much hemp. look up the power density of hemp batteries and I see an energy density of about 20 watts/kg. A Tesla Model 3 has about 80kWh pack. So if the battery were made of hemp the weight would be 4000 kg or 9000 lbs, or 9X ...

RE: What are some technologies that you would like to see covered more in Solar Today?

Posted By David Hrivnak 04-08-2023 12:20 PM
Found In Egroup: Everything Solar Forum \ view thread
I think you would be surprised how many would benefit from HP water heaters. Even in northern climates with a hot water heater in the basement where even from subgrade 55F walls they work well. Yes a little undesirable cooling in the winter, but then you get dehumidification in the summer. I see many ...

RE: What are some technologies that you would like to see covered more in Solar Today?

Posted By David Hrivnak 03-30-2023 05:34 AM
Found In Egroup: Everything Solar Forum \ view thread
William, first thank you and apology accepted. That said please do not discount what many small actions can lead up to. This hit home very much when I lead an energy task force at our Church. In the main sancuary we replaced some 50 300W spot lights with 26W LED Sylvania Night Chasers. We then replaced ...

RE: What are some technologies that you would like to see covered more in Solar Today?

Posted By David Hrivnak 03-28-2023 02:34 PM
Found In Egroup: Everything Solar Forum \ view thread
M Keith, if true the built foor area will expand 50% that seems to be totally different and will need to be addressed separately. And in many areas there is excess wind at night. Batteries are coming on strong and personally I have solar and as such I typically charge during the day when I have excess ...

RE: What are some technologies that you would like to see covered more in Solar Today?

Posted By David Hrivnak 03-27-2023 06:35 PM
Found In Egroup: Everything Solar Forum \ view thread
On the answer to # 4 what about moving transport to electric, consider the following options. But even if we move to a clean electric grid, many people claim that the grid will not be able to handle the growth in EV's. With many states moving to gas free car sales by 2035, could the grid handle the ...

RE: What are some technologies that you would like to see covered more in Solar Today?

Posted By David Hrivnak 03-27-2023 06:11 PM
Found In Egroup: Everything Solar Forum \ view thread
A combination of passive and some active PV, has been a winning combination for many. HP water heaters are amazing. I tell possible customers that I am happy to sell them the 8 solar panels it takes to power a typical hot water heater. Or I can sell you two solar panels to power a Heat Pump Water Heater. ...

RE: Issues With My solar System Help

Posted By David Hrivnak 02-01-2023 05:45 AM
Found In Egroup: Everything Solar Forum \ view thread
Run PVWatts from the National Renewable Energy Labs as I have found it to be the most accurate predicter of what a system will make. It is fairly easy to use and appears to work around the world. PVWatts Nrel remove preview PVWatts Estimates the energy production and cost of energy of ...

RE: EV's, the other half of solar. Reality EV.

Posted By David Hrivnak 12-01-2022 05:20 AM
Found In Egroup: Everything Solar Forum \ view thread
While SolarEdge may work that way with EV charging, I too suspect that is a configuration issue. I have been testing with a FranklinWH (Franklin Whole Home) and they have three smart circuits that one can configure. I dedicated one circuit (80 amp) to my EV charging subpanel where I have three NEMA 14-50 ...

RE: EV's, the other half of solar. Reality EV.

Posted By David Hrivnak 12-01-2022 05:13 AM
Found In Egroup: Everything Solar Forum \ view thread
While SolarEdge may work that way with EV charging, I too suspect that is a configuration issue. I have been testing with a FranklinWH (Franklin Whole Home) and they have three smart circuits that one can configure. I dedicated one circuit (80 amp) to my EV charging subpanel where I have three NEMA 14-50 ...

RE: EV's, the other half of solar. Reality EV.

Posted By David Hrivnak 11-25-2022 03:29 PM
Found In Egroup: Everything Solar Forum \ view thread
Yes I most often charge on Solar. We have enough PV on the house to power both the home and both plug in cars. I typically back off the charging amps to about 20 to better match the solar gain with charging. Then in Asheville NC and in ORNL in Knoxville I have charged on solar canopies they have open ...

RE: Zoom Discussion - Preparing for your Electric Vehicle: Will 400 Amp service be the new normal?

Posted By David Hrivnak 11-10-2022 06:29 PM
Found In Egroup: Everything Solar Forum \ view thread
No need for 400 amps. We have been charging 2+ EV's for over 7 years now on a 200 amp feed and never had an issue in our all electric home. Yes it will depend on your other appliances but we average 1600 EV miles a month from our home and from my measurements we have never been close to pushing our electrical ...

RE: Tesla Batteries-lightning fried them

Posted By David Hrivnak 10-28-2022 06:40 PM
Found In Egroup: Everything Solar Forum \ view thread
And it may not only be Tesla. We had a Generac customer lose a battery and inverter in what appeared to be a lightening strike. Generac did step up and replace the equipment, but they were fried. Along with a hot tub and other equipment. ------------------------------ David Hrivnak Sales/Engineering ...

RE: Questions

Posted By David Hrivnak 06-16-2022 05:58 PM
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But batteries add a good 50% to the cost of a system. So batteries are great AND expensive. ------------------------------ David Hrivnak Sales/Engineering EcoLogical (part time) dhrivnak@chartertn.net ------------------------------

RE: Questions

Posted By David Hrivnak 06-16-2022 03:54 PM
Found In Egroup: Everything Solar Forum \ view thread
If you do not have a bi-directional meter it will not know the direction of an electron. So if you feed the grid with a standard meter you will be charged full retail rates for everything you use AND everything you put back on the grid. Some utilities, TVA being a prime example adds so many fees and ...

RE: What's wrong with tracking on large solar arrays?

Posted By David Hrivnak 03-17-2022 05:12 PM
Found In Egroup: Everything Solar Forum \ view thread
There is nothing wrong with tracking per-say. It is just that extra movmement adds GREATLY to the cost of a system and then adds maintenance to what is normally maintenance free. It is just much more cost effective to add a few more panels to a fixed array. ------------------------------ David Hrivnak ...

RE: PV Fossil Free Residential Systems for Cold Mountain Climates

Posted By David Hrivnak 01-27-2022 06:28 AM
Found In Egroup: Everything Solar Forum \ view thread
We have used Fortress Power (LiFePO4) 48v batteries with success. ------------------------------ David Hrivnak Sales/Engineering EcoLogical (part time) dhrivnak@chartertn.net ------------------------------

RE: PV Fossil Free Residential Systems for Cold Mountain Climates

Posted By David Hrivnak 01-27-2022 06:27 AM
Found In Library: Everything Solar Forum

RE: PV Fossil Free Residential Systems for Cold Mountain Climates

Posted By David Hrivnak 01-25-2022 07:55 PM
Found In Egroup: Everything Solar Forum \ view thread
Yes but it is expensive. A customer of ours built a very tight well insulated home of about 1750 sqft in the mountains of SW VA. If they had net metering I would have likely installed a 9kW system, but being off grid we installed 13 kW, as we needed to make sure we covered during the winter, and we added ...

RE: Sharp ND-N2ECU and ND 72 EL(R)UDF Panels

Posted By David Hrivnak 12-09-2021 10:27 AM
Found In Egroup: Everything Solar Forum \ view thread
My understanding is that if you do not have optimizers, and thus use a simple string inverter, you are limited to the weakest cell. So if you mix say a 100 watt panel with three 200 watt panels your inverter will only see 400 watts, (100 x 4 panels). So it is not that you cannot mix but when you do it ...