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What to buy first - looking to scale my system over time

england

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Hi Everyone,

Moved to Texas recently and am concerned we'll have a repeat of last winter. Looking for a grid-connected battery backup (UPS) for now, which would allow me to add solar in the future. In July, my energy bill reported 2,900 kWh for the month and in October it was 1,800 kWh - not looking to support all of this now, just something to keep the fridge and lights on in case of a blackout. I got a few quotes from solar people that were around $50k, which is outside my budget for now.

So my question is what should I buy? Max budget around $5k this year (including install), but plan to add more in the future:
  • Battery - what type/size/etc?
  • Transfer Switch - not sure if automatic, manual, or something else is needed
    • How much should I expect to pay for this installation?
  • Inverter - do I need this now, or can it wait?
  • Solar panels - future plan to add/install.

I'm also considering getting a transfer switch installed and a generator that I can plugin, although ideally, I can go with an electric system.

Any advice would be greatly appreciated!


Thank you very much!
 
50k for solar panels? Seems high. How about a smaller system of maybe 3 kW of panels? Add a battery and you should be less than half of that cost. Pretty sure you still get some tax credit and it will reduce your energy bill every single month with or without outages. The system eventually pays for itself. That is where I would start even if you need to borrow some of the money. You do not need to max out the solar and reduce your bill to zero to get a great return on investment. Often solar installers will oversell what is needed.
 
2,900 kWh for the month
96.6kWh per day if divided by 30 days. WOW, I use between 3.5-4.0kWh a day and am 100% offgrid.
1St Rule of Energy is that Conservation is FAR CHEAPER than Generation & Storage ! Start looking at the Nasties in that home, AC, fridge/Freezer, water pump(s), Pool Pump (Evil & notorious power pigs, should use Variable Speed pump) and ALSO Identify all "motors" which can be converted to Soft-Start to prevent huge inrush surge demands.

AIO's (All in Ones) provide Solar Controller, Inverter & Charger all in one unit. They are modular internally and repairable (good brands). Quick Overview by Will: https://www.mobile-solarpower.com/all-in-one-122448v-packages.html

You can build a system over time BUT like a House, the system foundation has to support what you will put on top of it... You will require a 48V+ System given your loads, even if you goto frugal mode, that place is an obvious energy pig. A 48V Battery system @ 250A can deliver 12,000W which translates into 240VAC/50A (uncorrected for inverter inefficiencies). Good AIO's such as those by Growatt can be "stacked" to increase the amount of Watts/Amps available to the home.

  • Battery - what type/size/etc?
  • Transfer Switch - not sure if automatic, manual, or something else is needed
    • How much should I expect to pay for this installation?
  • Inverter - do I need this now, or can it wait?
  • Solar panels - future plan to add/install.

  • LFP (LiFePO4) safest & most affordable Lithium Battery. 48V System.
  • Transfer Switches are built into most AIO's. Some have dual AC Input, 1-Grid and 1-GenSet. Most also have an AGS (Auto Gen Start port) that uses a GSCM (Generator Start Control Module) to Start & Stop a generator. NOT ALL GENSETS WORK WITH THIS TECH ! see below
  • Inverter is what converts DC to AC, so if you want to run AC devices...
Atkinson Electronics & Controls makes one of the best, see this PDF for a list of supported generators (search the name & model) http://atkinsonelectronics.com/content/product_pdfs/All Hookup Diagrams Merged.pdf

Installation....
Take all equipment, add up the costs, add 45% and that is what Installation will cost you IF NOT MORE if you provide equipment. Do note that most installers sell equipment at MSRP and some even higher than MSRP ! Installation, Inspections, Permits do easily add 35-55% on top of hardware costs.

Equipment costs can vary a LOT... 1St Tier products like Victron, Schneider/Eaton of course carry a premium price but you get what you pay for,. 2nd Tier stuff like Growatt is very good and at both quality & cost, then there is 3rd Tier & Value... then bargain basement stuff to not so bad stuff, not for a proper residential setup....

Batteries.... Oivey ! Prices & Availability a problem. DIY is Cheapest and carries some risk, especially if cheap overrules common sense. Pre-assembled packs can be a good deal, again this is an area where we deal with Known Good Vendors as there are many sheisters out there. Big Commercial company packs are well backed with warranties and assorted certifications but of course you'll be paying for that.

TIP: In most places, anything Grid Connected has to comply with the local rules & regs. and most especially if you want Insurance ! (I have nothing good to say about insurance companies) Most will want that UL/ETL/CSA-US Stampings & certificates. This can apply to everything from the batteries on up. WARNING: If looking to purchase equipment NOTE THE DETAILS ! There are Models for Global Use and so Certifications vary from NONE to ALL OF THEM and various... The devil is in the details ! ALSO be aware that EU is 220VAC@50Hz while Texass is 240VAC/60Hz do not confuse non US gear.
 
For just a starting point that can power the fridge, and various small loads, get a 3000W inverter and a 5KWh 24v battery.
Have an electrician build you a breakout box, and hook it up when needed...
 
Thanks for the responses! I have 2 AC units (a 4-ton and 2-ton), and a pool with both a pump and blower pump - feel like these items account for my high energy usage. I ended up buying a gas/propane generator that I can use in case of emergencies, which will give me more time to buy and build out a solar/battery system.

Thanks again for all of the recommendations!
 
There is NO DOUBT that the AC & pool pumps are your biggest power hogs. You didn't mention heating though. Many can be retrofit with just new variable speed motors but not all, it's worth looking into AND if these are older and already worn to a certain point, it may be a prudent & timely update/upgrade. That will save you money in power costs in any case.

Hot Water heating is notorious, so many are hooked on the idea of Big Tanks full of hot water. Do we leave a car idling in the driveway 7/24 just because we might want a 10 minute drive somewhere ? On-Demand water heaters work amazingly well, Takagi, Bosch and many more are excellent products that do the job. I have two in fact, 1 dedicated to my Radiant Heating system (uses propylene glycol) and one for my hot water supply. Trick is to locate the heater close to the "use points" and do insulate the plumbing, it really makes a BIG difference.

Work out a Priority List of "necessities" that you want to power constantly and are if they on circuits which can be transferred to a separate sub-panel. Next is to figure out how much power those things require and that's a good starting point. Start with "need" first and work out from there.

There are both Inverter & AIO Systems that are capable of using Grid AC / GEN AC that are programmable to operate in various modes, including UPS (Uninteruptable Power Supply), as well as others. People are using such for "Peak Shaving" their Time of Use rates by charging batteries during low rate periods and then running their equipment from battery during high rate times.

The advantage of such a system, is that you are NOT pushing to grid, which makes life a boatload easier ! You can add solar to it to charge the batteries, expand the batteries & stack on another inverter and switch more "household load" to the separate system over time. Now of course that all depends on if you want to DIY or partly DIY with a "friendly cooperative) electrician to certify it or not... again pending on you and what you need/want and have to have.

But honestly, the really important thing to work out first is "where the hell" all that power going and seeing what can be changed to cut that down. Fight the right enemy first !

Good Luck
 
looking to scale my system over time
One of the nicest things about microinverters like Enphase is you can get started with Solar for an incredibly low-cost upfront, and then continue to scale up as little as one panel at a time.

Microinverters look more expensive than inverters, but they bring a few extra things to the table, and when you factor in the built-in things like MPPTs and RSID costs start to become comparable.

The first big advantage is that if one dies, all the rest are still making power so you're out very little power, they're fairly easy to replace. A typical string inverter usually has a 5 to 10-year warranty, microinverters typically have very long warranties (e.g., Enphase offers a 25-year warranty). The microinverters go behind the panels, so they don't take up any space and are rated to be outdoors. They automatically shut down when the grid isn't detected so don't need auxiliary shutoffs. They typically have a lower voltage and are generally more efficient and more reliable, they can scale up to any size. They have per panel diagnostics and are easy to mix/match panels of different sizes/vendors or to grow/expand a system.

Batteries are more of an issue with them, currently, AFAIK, only Tesla and Enphase have batteries with "brains" to natively control microinverters. Supposedly, sometime this month the Ensemble configuration will be compatible with standby emergency generators. The Ensemble batteries also can't go below freezing, although that might change with the upcoming Ensemble 2.0.

...around $50k, which is outside my budget for now....
You might be interested in @upnorthandpersonal's thread about his a 10kW solar system with 28kWh LiFePO4 battery, inverter, BMS and charge controllers for under $12k U.S. dollars.
 
Hi Everyone,

Moved to Texas recently and am concerned we'll have a repeat of last winter. Looking for a grid-connected battery backup (UPS) for now, which would allow me to add solar in the future. In July, my energy bill reported 2,900 kWh for the month and in October it was 1,800 kWh - not looking to support all of this now, just something to keep the fridge and lights on in case of a blackout. I got a few quotes from solar people that were around $50k, which is outside my budget for now.

So my question is what should I buy? Max budget around $5k this year (including install), but plan to add more in the future:
  • Battery - what type/size/etc?
  • Transfer Switch - not sure if automatic, manual, or something else is needed
    • How much should I expect to pay for this installation?
  • Inverter - do I need this now, or can it wait?
  • Solar panels - future plan to add/install.

I'm also considering getting a transfer switch installed and a generator that I can plugin, although ideally, I can go with an electric system.

Any advice would be greatly appreciated!


Thank you very much!
OMG, 2900kWh a month ??
Energy saving is your biggest priority.
Pool cover? (Swimming pools are a massive energy pit)
You don't need to have the pump on 24/7 (often a 1 to 2KW motor), and solar thermal heating is cheap to install.
If a pool is just a couple of degrees above ambient the energy loss climbs dramatically because of evaporation.

When it comes to reducing energy costs/consumption the saying is "Fabric First". Improve the building to reduce the energy footprint.
This is usually a more cost-effective route.
Once you have made everything more efficient, then look at how to power from renewables.
1) Look at how everything is controlled and if it can be turned OFF for more hours each day.
2) Look at the efficiency of equipment you have. (Some old gear is very bad)
3) IMPROVE INSULATION (it works both ways).
4) Use renewable sources of energy. (Solar thermal can be very efficient)

I have in the past implemented a Solar thermal/heat pump system on an outdoor pool before, and it dropped the energy costs dramatically.
I worked out the cost on delivered heat to be 1 to 2p per kWh (the SPF was around 8 to 9).
 
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