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Is Storage Worth the Investment?

  • 1.  Is Storage Worth the Investment?

    Posted 12-05-2022 02:08 PM
    Hello, everyone!

    So, as I research further and further into Solar Technologies, I find myself asking questions which I cannot answer myself. While I have my personal opinions on various subjects, it is always a good idea to get some feedback from others with similar passions for renewables such as solar energy.

    After learning aspects of Solar PV system design, it is abundantly clear the major heavy hitter in terms of finances is the inclusion of storage with solar systems (or renewables of any kind for that matter). While grants and rebates are present in most states (along with the Federal ITC rebate at 30%) help alleviate the financial burden, I was wondering how this community felt about the inclusion of storage methods with solar systems. While I feel it would be ideal, there are some situations in which the inclusion of storage could be too financially debilitating for a current investment, especially since battery life of some of the more economical versions of storage don't hold up to the system's array/inverter life.

    Simple version of my question: Is storage worth the current investment in your opinion? Should it be a consideration for MOST people looking to purchase a solar PV system?

    Thanks for your input!

    ------------------------------
    Nathan Freeman
    Student
    ASES Technical Divisions
    Milford DE
    ------------------------------


  • 2.  RE: Is Storage Worth the Investment?

    Posted 12-06-2022 02:51 AM
    Hi,

    First, storage is a necessity, not a choice. Besides the financial cost, the round-trip efficiency of the storage system can be around 80% so a nonnegligible amount of energy is lost. Electricity from PV or any other source must be used directly as much as possible to avoid losses during storage.

    Second, when storage becomes unavoidable, (eg.: to cover nighttime usage ) its size can still be minimized using various energy management systems.

    Third, the answer to your question depends on the objective of the person who is considering storage. is it for money saving, is it for good environmental action? is it for energy security and reliability?
    If the objective is for money saving then by principle no need to invest. You can still evaluate the time of use rates to see if storing energy at low tariff to use or sell when the tariff is high make sense
    If the objective is to save the planet and have a reliable green energy supply then go for it. 

    Lastly, please notice that there are other options for energy storage, not just lithium batteries. For cooling or heating, you can use thermal energy storage. For electricity, I think we should move to community-scale storage solutions as we did with community solar PV. At this scale, pumped hydro storage, redox flow battery, and other emerging technologies can offer more competitive pricing than lithium batteries. 

    I hope your question has been answer

    Best regards

    ------------------------------
    Elias OUEDRAOGO
    Senior R&D engineer
    ------------------------------



  • 3.  RE: Is Storage Worth the Investment?

    Silver
    Contributor
    Posted 12-06-2022 10:26 AM
    First off....HI... and welcome to the world of RE (Renewable Energy). Most people will find that entry into this world accompanied with action, results in the very least a feeling of good and well being.

    Starting at the engineering level, emotions, environmental, etc. concerns aside, storage is a tough consideration unless you are off grid, where it becomes one with your off grid choice. 

    Solar electricity or PV can go direct to grid without storage as most people choose. The ITC in the past has given up to 30% for all those system costs. With the Inflation Reduction Act (Anorexic version of 'Build Back Better'), storage greater then 4KWH is taken into the equation for credit. AS you noted, this takes quite a bite out of the cost, though not a garage sale. 

    Shifting to the NEED perspective, the main benefit with storage is you get power when the grid goes down (I will assume you are on grid). If you are in an area with fixed KWH fees and rates, your battery bank (Whatever chem) will sit in a float state 99% of the time. This is where I find myself to date, recently updating my lead-acid wet batteries (7-9 year) to a Rolls OPzV gell solution which is reported to be able to survive 20+ years in a "float" application. I run about 40KWH tot..

    Rolls OPzV gel battery C-20 785AH model

    That is the direct link to the spec sheet of the battery I chose. I am merely giving this as an example for what I chose for my specific application, backup power. They are made up in Springhill, Nova Scotia.

    Cost was approximately 250$ per KWH including cables, shipping, etc..
    Now with the ITC (30%) it would be reduced to ~175$ per KWH.

    My decision to have RE backup power is that it is consistent with my choice for a net zero or better living structure, which includes all my transportation as well. This of course assumes my choice of having backup power in the first place. In my location we have very short outages from time to time, maybe 6 times a year with the possibility of one in the 24-48 hour range. 
    SO I guess my first thought would be, how is power stability at your location?  
    Then do you feel the need for backup power? (Life style configuration).
    Followed by do you want an RE solution or a more traditional "Generac" solution?, though they as well have started offering inverter battery based solutions with varying options.

    The last choice I guess would be Greta or Capitalism. Who rules? (A little intended humor).

    The last financial calculation would be if you live in a TOU environment with enough variance (Should be real big) to make it worth while to cover a Lithium solution (Better than Lead here) cycling batteries everyday. To get 20+ year Lithium's is going to cost you, considering the duty cycles and DOD's. Choose carefully. Everyone is pushing into this market now.

    I will stop there, for any more becomes a handbook...
    Keep asking questions and try to have fun along the way.....




    ------------------------------
    william fitch
    Owner
    www.WeAreSolar.com
    ------------------------------



  • 4.  RE: Is Storage Worth the Investment?

    Silver
    Contributor
    Posted 12-06-2022 12:06 PM
    Hey Nathan -
    As others have commented, often it is a matter of why storage is necessary.  But assuming storage is not essential (the grid is fairly reliable and the loads are not amazingly critical) - then I tend to take the "let's wait just a bit" approach. 

    If we are in the "floppy disk" age of solar, then we are in the "pen and paper" age of batteries.  They are just now beginning to be affordable - but the technology is rapidly changing and rapidly getting cheaper. 

    So I would design the system to be "battery ready" - but hold off a couple of years to see what battery technology is going to do.  It may be the future "go to" storage device will be an electric vehicle.

    Jay Warmke
    SolarPVtraining.com


    ------------------------------
    Jay Warmke
    Owner
    Blue Rock Station LLC
    ------------------------------



  • 5.  RE: Is Storage Worth the Investment?

    ASES Life Member
    Posted 12-07-2022 09:10 AM
    Hi Jay!
    Can you share any more specifics about a battery-ready system?
    Thanks!
    Carly

    ------------------------------
    Carly Rixham
    American Solar Energy Society
    Boulder CO
    ------------------------------



  • 6.  RE: Is Storage Worth the Investment?

    Silver
    Contributor
    Posted 12-08-2022 01:52 PM
    Hi Carly: Battery "ready" really just means have room in the sub panel for extra 240VAC breakers. Design the system as if you were putting in the battery, (Breakers, available space, wiring, etc.) but just don't. Within that, you could design for wide open AC coupling so you are not "brand" locked for adding down the road. Whatever you choose for your virgin sine wave inverter charger make sure it has been tested with the PV grid tie inverter for "playing nice" under various load types. Or, you could always go with the main PV grid tie inverter built into the battery ready inverter (Sol-Ark comes to mind for one) and simply wait to add batteries. The down side there is you are kind of "brand locking" your battery solution to the Sol-Ark battery spec. inverter. 
    At this state of technology whatever solution you choose, make sure the PV output, battery state and loads can be managed dynamically in grid down situations. Manual curtailment of the PV inverter in grid down situations is not a place you want to visit.

    ------------------------------
    william fitch
    Owner
    www.WeAreSolar.com
    ------------------------------



  • 7.  RE: Is Storage Worth the Investment?

    Posted 12-09-2022 12:02 PM
    Or, as an alternative, you can use a more efficient HYBRID inverter!! Lower losses because of fewer conversions, no need for extra breakers (especially if you use the new ones that are rated to PASS THROUGH FULL 200A service! )That way when the power is out YOU decide what to run without the need for "Supported load panels". And, most of the hybrids offer a WIDE VARIETY of operating modes, such as "local loads only- no export", or export limited to XXX (You select) watts, or my loads first, and anything left goes to the utility, and almost any combination you can imagine. Again MOST of them offer a nice color LCD display that actually monitors power in AND out (via in/out current transformers) and has a VERY INTUITIVE graphic display! AND best of all, there are no extra boxes or hardware required!! If you can't afford batteries just yet, they will work as a normal grid tied inverter. When you get the batteries, you just plug them in, connect the CANBUS (ethernet) plugs to the inverter, set the absorb and float voltages, and you're done!! JUST ONE BOX ON THE WALL, NO SUBPANEL NEEDED, AND MULTIPLE OPERATING MODES! Hookup panels, batteries and you're done. No extra INTERFACE HARDWARE required. It's the wave of the future. Consider looking at the 15K SOL-ARK "LIMITLESS"...   SOLAR OF ALL TYPES HAS NEVER BEEN EASIER!! I've installed 5 systems so far and they are bulletproof!! (but NOT "idiot" proof...)

    ------------------------------
    Joe Utasi
    PV Solar Consultant
    Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
    ------------------------------



  • 8.  RE: Is Storage Worth the Investment?

    ASES Award Winner
    Posted 12-11-2022 02:43 AM
    Jay, I disagree.  The grid is becoming less reliable (I teach a graduate course on this).
    In the digital age and with hotter summers and colder winters in a good part of the country,
      being without power is not an acceptable alternative when you have western summer
      days crossing 100 deg F and wind snaps in areas not prepared,
    In the last two years, we have had long term major grid shutdowns in Texas, Louisiana,
      Puerto Rico, huge parts of California, this past week on the sniper attach on the two 
      North Carolina sub stations where outages are over a week, and many more.
    In fact it is not going to get better for quite awhile.

    In my 22 years old clean owner's rep business focussed on commercial/industrial,
      government/military, and infrastructure/health/first-responder -- solar, wind, biomass
      batteries and smart sensors and controls are essential.  And while I don't guide on
      residential, I do guide builders on small commercial/residential - and in the southwest
      US, Gulf Coast (SE US), I absolutely recommend renewable systems tied to batteries. 
      Several residential large-scale builders in TX, will now include PV-battery banks in
      new constructions, focussed on continuity-of -operations (not whole house).

    Best regards, Scott

    Scott Sklar
    President
    The Stella Group, Ltd.
    706 North Ivy Street, Arlington, VA 22201
    VA Phone:  703-522-1195 (3049 direct)
    E-mail:   solarsklar@aol.com
     
    The Stella Group, Ltd.. is a global strategic technology optimization owner's rep firm for 
    clean energy users and companies, with a focus on system standardization, 
    modularity and web-enabled diagnostics.  Scott Sklar is an Adjunct Professor at 
    The George Washington University teaching three unique interdisciplinary 
    sustainable energy courses, and an Affiliated Professor with CATIE, an 
    international graduate university in Costa Rica offering graduate degrees
    on sustainability. Sklar is the Sustainable Energy Director at GWU's Environment 
    and Energy Management Institute (EEMI). ). and his summer graduate GWU course
    "Renewable Energy & Critical Infrastructure" is the first such course in the USA.









  • 9.  RE: Is Storage Worth the Investment?

    Silver
    Contributor
    Posted 12-11-2022 03:36 AM
    Scott -

    I don't disagree with your premise that weather extremes and an increasingly unreliable grid make the integration of local storage more and common and necessary.  As prices fall, we may see some level of storage integrated into nearly every system. 

    But that doesn't address the issue of whether or not it makes financial sense for ME to integrate storage into MY system.  Unless I am faced with an unreliable grid today (I know the grid is potentially unreliable, but have I experienced it), or my loads are so critical that an outage is unacceptable (in which case a generator may still be, economically at least, a "better" decision) then it may be the better economic decision to wait a couple of years on battery technology to evolve (and hopefully become more affordable).

    I do a lot of evaluations where we price out a simple grid-tied residential system (say a 6 kW system) and before incentives it comes in around $15,000 - $18,000.  The customer then asks about battery backup.  They think it would kind of be nice, but their grid has not been a problem.  Adding batteries will add $10,000 (minimum) to the bid.  At least nine out of ten times the cost benefit is not there.

    But for a couple hundred dollars you can design the system to be ready for battery integration in the future if the grid becomes less reliable or if the local utility institutes time-of-use pricing or if their net metering agreement becomes less generous.  Well, that's generally the most sensible option unless your budget is unlimited.

    Clearly more and more systems are integrating batteries because of extreme weather events (fire in CA, hurricanes in PR, cold weather in TX), time-of-use pricing policies and restrictive net metering policies - but if these trends to not currently apply in your situation, then a "prepare for but wait" approach my be the sensible option.

    Jay Warmke

    ------------------------------
    Jay Warmke
    Owner
    Blue Rock Station LLC
    ------------------------------



  • 10.  RE: Is Storage Worth the Investment?

    Posted 12-11-2022 04:00 AM
    Hi,

    As Scott said, the grid is becoming less reliable. With more tech going into the grid, it represents system operation improvement opportunities, however, there are also associated vulnerabilities that can be technical or man-made. Transitioning to 100% solar and wind (both intermittent ) without well-sized, well-distributed energy storage systems will add grid stability issues. As I stated in an earlier post, energy storage will become a necessity soon, so better be prepared to include it in projects. 

    The cost of a lithium battery can be relatively expensive now, however, you can start by using a small pack of 3-5 kWh to cover the small loads (lighting, phones, laptop, router) for 1-2 days. In the future, batteries may become an affordable option, or community-scale energy storage may emerge as a more cost-effective solution. I think having more grid-connected mini-grids each with 10-24 hours of storage will be the optimum solution financially and in terms of grid resilience. Hard to predict in which direction things will unfold!

    Whatever the future will look like, it is always good to have a small backup while waiting for an eventual rescue. You can see home batteries like paying for insurance, it looks not valuable until the day you are in trouble. 

    Best regards

    ------------------------------
    Elias OUEDRAOGO
    Senior R&D engineer
    Algebra Global Technologies
    ------------------------------



  • 11.  RE: Is Storage Worth the Investment?

    Silver
    Contributor
    Posted 12-11-2022 07:19 AM
    Edited by william fitch 12-11-2022 08:40 AM
    HI: I think everyone here knows storage is an engineering positive in bringing the long term plan together for an RE world. For some people the cost is not a question of which OPTION of storage I choose, but whether I can afford it at all. If a person has enough money for grid tie that can continue the displacement of FF's, which is the whole reason we are all doing this in the first place, they should not be made to feel that it's storage or nothing. Do we really want people saying, "Oh I can not afford storage so I will do nothing.". I sure as hell don't. 

    I notice your company reference puts you in Turkey. I will assume you are there as well. I know people's "felling's" regarding "the world" are 99% based on their own physical environment. Since I have not heavily researched Turkey's grid and having never lived or visited, based on your "feelings presented", I would guess you have lots of stability issues. That has to really suck day to day. 

    I think each person has to do what they can afford to do when they can afford it. With the right gov incentives, technological developments and invention hopefully we will get there sooner than too late displacing FF's.

    ------------------------------
    william fitch
    Owner
    www.WeAreSolar.com
    ------------------------------



  • 12.  RE: Is Storage Worth the Investment?

    Silver
    Contributor
    Posted 12-12-2022 03:41 AM
    Carly - the devil is always in the detail, eh?  California currently requires new residential facilities be "battery ready" and they define this as having a 225-amp busbar service panel (minimum), a minimum of four backed-up circuits (two of which must be the refrigerator and bedroom receptacle outlet), and also a subpanel or a split-bus main panel for those circuits.

    Given changes going on in load management technology - not sure if a separate sub-panel will be necessary in the future (likely we can handle that with software).  It reminds me of years ago when I wired a home with Cat5, Coax and fiber cable to each room with a big patch panel in the utility area - then all my electronics ended up being wireless.

    I am going through this very exercise on a small commercial property we own.  My plan is to install a utility disconnect at the meter (with a 400 A main disconnect and then 4-8 double-pole breakers below).  I will run 100 A service to the solar canopy (even though I think the array will max out at 45A) and 100A serve to an EV charging station.   New rules require the batteries be outdoors (for all practical purposes), so I need to make sure there is space and a place to hook them in, plus a transfer switch (or inverter with transfer built in).  So the utility meter area will become quite crowded. 

    Probably some holes in the plan, but that is where my head is at at this stage.
    Jay Warmke



    ------------------------------
    Jay Warmke
    Owner
    Blue Rock Station LLC
    ------------------------------



  • 13.  RE: Is Storage Worth the Investment?

    Silver
    Contributor
    Posted 12-12-2022 06:30 AM
    God Jay. What a mess. Over regulation and over cost. Just makes things more expensive than they already are for poor thought out engineering and excess. Using a dump truck to fill a bath tub. And they wonder why people hate to see, and accuse Gov. of bad dealings and over regulation.

    ------------------------------
    william fitch
    Owner
    www.WeAreSolar.com
    ------------------------------



  • 14.  RE: Is Storage Worth the Investment?

    Silver
    Contributor
    Posted 12-12-2022 06:54 AM
    Yeah.  Easy to get cynical.  Of course a great deal of the problem is that we are trying to design 25-year systems in an industry where the technology changes (dramatically) every three or four years.

    Jay

    ------------------------------
    Jay Warmke
    Owner
    Blue Rock Station LLC
    ------------------------------



  • 15.  RE: Is Storage Worth the Investment?

    Posted 12-12-2022 01:43 PM
    I would like to see some of these be adopted across all states, and by the manufacturers of electrical equipment.  The 225A minimum busbar requirement is a good start, but better to be 250A on panels with a 200A main breaker.  This would enable more solar to land on back-fed breaker, but does not really help with battery storage as much.
    Requiring split-bus panels on all new builds would be helpful, with the ability to mount a contactor either in the box across the bus terminals or to easily wire an external contactor, with direction to land critical circuits such as you describe on the side that can be islanded from the grid.
    Encouraging all electrical distribution manufacturers to develop smart breakers to shed loads, AND standardize on communication/control protocols used to interface with them so that different storage and inverter manufacturers could control them as part of a more intelligent control system.
    The limitations on ESS that force many installs to be outdoors as you mention do not work in many states.  They need to raise the kWh limit that can be installed in utility areas if the goal is large scale adoption in colder climates.

    ------------------------------
    Ken Nadsady
    AviSun Renewable Energy
    Hudson OH
    ------------------------------



  • 16.  RE: Is Storage Worth the Investment?

    Posted 12-12-2022 02:25 PM
    And, be informed that LiFePo4 batteries (That most solar backups are currently using) do NOT take kindly to temperatures below 32 degrees. That means the upper half of the USA needs to provide insulation and some minimal heating to batteries OUTSIDE the house envelope. Hopefully, the installers doing these battery installs are aware of the temperature limitations!!

    ------------------------------
    Joe Utasi
    PV Solar Consultant
    Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
    ------------------------------



  • 17.  RE: Is Storage Worth the Investment?

    Posted 12-06-2022 09:42 PM
    Nathan, that is a very good question, but I am afraid there is not a simple answer.  I agree with you that storage remains to be relatively high cost, and has not really yet experienced the same downward trajectory that solar PV has. It may never be that dramatic, I don't know.
    I think the answer to your question will depend on a few things.  First, it will depend on how the cost of energy is calculated in a specific region, and what the net metering policy is.  If there is full net metering, and no time of use rates, and no demand charges, and no export limitations, then storage will not make sense for most people in that region.  If net metering policies are less solar friendly, and if rates vary by time of day, then storage will likely make sense, since you can dispatch from battery to increase self consumption or reduce import during peak rate times.
    Second, it will depend on the value a customer places on having power when the grid is unavailable, which is often related to how often grid outages occur, and the duration for which they last.  The value that storage brings for battery backup is often not for any financial return, but for comfort, or for protecting critical systems, such as medical machinery, or preventing food loss.
    In Ohio, where we generally have good net metering laws and no time of use rates, MOST people choose not to install batteries, although the number that are installaing them has been increasing recently, and most people are at least interested enough to ask for it in the quote.
    For commercial systems, where there are demand charges, the economics are getting better for installing storage, especially for certain usage profiles.

    ------------------------------
    Ken Nadsady
    AviSun Renewable Energy
    Hudson OH
    ------------------------------



  • 18.  RE: Is Storage Worth the Investment?

    Posted 12-07-2022 11:25 AM
    Edited by Michael Mayhew 12-13-2022 11:18 AM
    My home in Maine is connected to a very stable electric distribution system and the state has Net energy billing, and my town has a huge summer tourist load.  Having a total battery backup system generally decreases the energy efficiency of PV systems by about 20%, while increasing the installed cost by more than 50% and creates a localized hazardous waste with a useful working life of about 10 years.  I have had an extremely small battery bank used to run my radiant floor zone pumps which combined with a small PV powered pump for my solar hot water system kept me cozy for a decade, until I changed out the SHW system's DC pump for an AC unit.  I considered adding enough to the battery bank to provide back-up power for my refrigerator but decided that purchasing a 3 kW portable gas generator might be a better investment.  After owning the generator for a decade, its only runtime was when it was loaned to my in-laws after a serious ice storm.  I gave it to one of my children a decade ago and have never missed it.  (I fail to understand why people invest 10s of thousands of dollars to install residential generators.  That same investment could save/earn them income if it was used to increase their solar electric systems to approach a net zero energy scenario and the world would be a better place.) I do also happen to have sleep apnea but have found that a very small battery charger ($50?) on my nightstand keeps away the bogyman. 
    I can understand having a prioritized circuit that might have a battery bank or a UPS for critical loads, but let's remember our great grandparents survived quite nicely in the early Victorian period before rural electrification, so spending a couple hours with candles and playing cards every couple of seasons might not kill you. I'm all for mechanical storage systems and super insulated homes but have a problem with providing battery banks for powering pool pumps that probably should be cycled off more than they are.  Doing more with less is good business and your grandchildren might be glad that the environment is slightly better off.  Peace, Love and happy holidays my friends.  


    ------------------------------
    Michael Mayhew
    President, Sr. Energy Engineer
    Heliotropic Technologies
    ------------------------------



  • 19.  RE: Is Storage Worth the Investment?

    Posted 12-12-2022 02:58 PM

    Sorry to be late to the thread, but for some reason the email digest just arrived today. Here is my 2 cents. I have 7.67 kW solar, 2 Tesla Powerwalls, and 2 EVs (a Bolt and a Rivian). We have had solar for 5 years. We live on the NC coast (mild year-round climate) so hurricane resilience is an important factor to me. Our original install was 4.35 kW and one Powerwall. We added panels as we saw how it worked, and the second Powerwall.

    First some background then my views on residential storage. When we installed, our utility's "solar plan" was buy all at avoided cost, sell to us at retail. I wanted solar for environmental reasons, and the only way it made any sense was to do 100% self consumption. Sometimes we curtailed. These days with 2 EVs, we can suck up everything generated. We have a gas (propane) stove/oven, everything thing else is electric. We've made around 70% of our power this year, including at-home EV charging. Consumption (projected to year end) around 13.4 MWH for the year, production around 9.4 MWH (Note our most recent upgrade was in early May this year, with 1.6 kW panels and the 2nd Powerwall, and I'm expecting to pick up about another 500+ kWh with a full year). We have tree shading in the winter, and we have a third of our panel capacity split between east  and west, with two thirds south facing.

    Our utility now offers ToU rates, but only if you have storage to avoid demand charges as well as higher kWh charges during peak times. The base rate is higher for the plans on offer, and there's very little upside and large potential demand charges if you make a mistake or run out of stored power due to weather. So we have stayed with our grandfathered plan. 

     

    But storage offers resilience that I'd otherwise need a whole house generator. My Powerwalls (25 kWh for two in round numbers) are full panel connected (i have enough LRA to start a heat pump off grid but in most situations would use space heaters as needed). We had one of the "shooting a substation" issues in November. We were only out for a couple hours fortunately, but we didn't even have to reset the clock on the microwave, the cutover was so quick. I didn't realize there was an overnight outage until I started reading social media (we keep a backup reserve in the Powerwalls, but otherwise use for balancing consumption with production). We've had several other outages of a few hours here and there. The last long outage (4 days) was from a hurricane 2018. There, it was so cloudy that after the Powerwall depleted after 24 hours (just one then), I had to use a portable generator (we were making just a couple kWh per day). The sun came out about the time the grid was restored.

    Tesla continues to improve the software features and flexibility of the Powerwall and IMHO has the most mature software stack of home battery vendors. Efficiency may be less, but they offer things like StormWatch, which will charge from the grid if a severe weather event is coming. They let you charge from the grid on demand if needed. The instantaneous monitoring is very effective. 


    The bottom line is that I'm very happy with my "whole house UPS." My total after tax credit cost for my system is under $33,000. I get about $900 off my power bill annually. And I didn't buy a $15,000 whole house generator. 


    Your experience may differ, this is my opinion and experience as a user(not an RE professional).


    -Joel 



    ------------------------------
    Joel Dunn
    Joel Dunn
    ------------------------------



  • 20.  RE: Is Storage Worth the Investment?

    Chapter Leader
    Posted 12-12-2022 02:40 PM
    Nathan -
         Thank you for the question ... "Simple answer, ... Yes" ! I have been using solar PV modules for over 40 years and we 'always' have a simple storage 'backup' (batteries) to get the power we need ... after the sun has set ! Of course there are other folks who question the reasoning I present. If you are operating a business that is 'only operating during daylight hours' ... you may not need battery storage ! If your budget is 'limited' and you don't want to over-extend your finances, you may have other options for storage (pumped-hydro for one). The options do get complicated and I try to 'keep it simple'.
         We also help folks to assemble their own solar PV for use in their businesses and homes, using 'blemished' ('full-power') PV cells, rejected by the robotic factories. This does allow the end cost to be reduced, you may feel good about the process involved as well as have the knowledge to diagnose, fix and otherwise reduce your expenses associated with using solar PV ... (of course 'off-grid' solar is the method I promote for those who assemble their own PV modules) ! The batteries can be 'inexpensive' ( EV 6V batteries are available for $155. each), and you can get a 'basic' storage set of 4, for less than $620. plus tax. We also have experience with a more expensive option which is approx double the lower cost 6V battery storage price.
          The other added cost is the balance of the system, ... mounting, wiring, inverter and options that may allow you more comfort, etc ! Please do include my 'simple answer' to your question concerning the 'value of battery storage for PV' ... as "Yes" ! Thank you

    ------------------------------
    John Burke
    Director, MESEA, Maine
    Maine Solar Energy Association; Downeast Alternative Design Solar, Inc
    Jonesport ME
    ------------------------------



  • 21.  RE: Is Storage Worth the Investment?

    Posted 12-12-2022 03:00 PM
    to answer your storage question...  The sad state of affairs in the USA and Russia and North Korea could easily escalate to a point where having storage will be a blessing. This doesn't mean you are a paranoid "prepper" - it only means that you have taken into account the above mentioned "sad state of affairs".  Only YOU can make the decision to go with storage. The newer LiFePo4 batteries will easily provide 20+ useful years of storage, so if you amortize the cost over that time period, your power "insurance" daily cost will be VERY affordable from an "insurance" standpoint. Other folks have suggested hydro - and this is the ULTIMATE power source for battery charging, as long as the "stream" runs all year. It doesn't need to be a LARGE flow - only enough to generate 10 or 15 amps of battery charging current. This also is a decision only YOU can make...

    ------------------------------
    Joe Utasi
    PV Solar Consultant
    Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
    ------------------------------



  • 22.  RE: Is Storage Worth the Investment?

    Posted 12-12-2022 03:40 PM
    Edited by Michael Mayhew 12-13-2022 11:19 AM
    I think that many of the recommendations here misunderstand the demand loads of the grid.  In the middle of the night threre is very little load.  Power purchases are a bargain for 3rd shift power and in the spring in the northern hemisphere, with winter snow melt power has virtually no value, as hydroelectric power provides more than the grid can use so generators are bypassed to keep water levels in the reserves manageable. In critical areas, there's plenty of solar energy that just needs to be harnessed. Batteries are needed, but only for critical circuits to reduce future potentially hazardous wastes and to keep first costs cost-effective.  Diversified renewable systems like tidal power and wind power can complement passive solar and solar electric systems for the small daily base loads.   Energy management and conservation synergies should be maximized, synergy as Bucky called it, should be maximized.  Doing more with less.  Peace, love & happiness folks.


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    Michael Mayhew
    President, Sr. Energy Engineer
    Heliotropic Technologies
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