I just installed an off-grid/pure-solar (no gas or wood heat) energy system for a couple that lives out in the country, north of Sacramento, where there is no grid power and no cost-effective way to get any. And the entire system cost just $14,000, for a self-powered, fully autonomous, pure-electric, solar-powered energy system for their 360sf $100,000 “tiny home”, which used 28kwhrs/day last winter, when they had it on a different nearby ranch, on grid power, and so had a year’s worth of energy use data to calculate with to help us design an adequate sized system.
$14,000 may seem like a lot, but they were spending $260/month on the ‘equalizer plan’ (same dollars per mo even though some months were obviously higher usage). And when you calculate how much they would’ve spent to stay on the grid (aside from the crazy money they’d have to spend to get the line to them), the total dollars in monthly utility payments would reach $14,000 in just 4yrs and 2 months!
yr 1: $260 x 12mo = $3,120
yr 2: with traditional 7% annual rate raise: $3,384
yr 3: “ $3,571
yr 4: “ $3,713…….total $13,788
yr 5: “ $3,972
yr 6: “ $4,250
yr 7: “ $4,547
yr 8: “ $4,865
yr 9: “ $5,205
yr 10: “$5,569
…….which equals a total of $42,196, ...just for the first ten years!
They are in their early 40’s and so would’ve been paying $42,000 every 10years, for the next four or five decades! But now they will be energy-free in four yrs, and never pay another dime for electricity, until about 3 or 4 decades, when some of the components may need replacing (and will be extremely cheap and commonplace by then)
The system only took a few days to install, and I am not highly experienced at this and had to go slow in many parts of it. But I believe that anyone can learn how to do this and avoid the high labor cost, just like we did. I showed them every detail of the work so that they will be able to know the system intimately and add-on to it if they want to (like if they buy an EV, etc.)
The system consisted of:
20 570w panels which cost $2,100 yielding an 11.4 rated kw array.
~$3,000 for unistrut racking with cement posts for the ground array.
A pair of these 6.5kw inverters for $1,600 (tot) in parallel which provides 13kw of power, and includes four 4,000watt capacity MPPT Solar Charge Controllers built in.
https://maximumsolar.online/
64 of these 310ah lifepo4 cells cost $3,892 (inc shipping and tax):
https://www.aliexpress.us/
…along with four of these Battery Management Systems for $145(tot)
https://www.aliexpress.us/
….provides four 16kwhr, 48volt, 16 cell series string, batt packs, in parallel, costing just $4,037, for a total of 64kwhrs of storage for cloudy days. ($63/kwhr)
Then another $800 or so for cabling, circuit breakers, bus bars, etc.
Which, with tax and some shipping and some incidentals, came to about $14,000.
The way the system works, ….the way all off-grid/pure-solar systems work… is to calculate how much energy is needed in mid-winter, because on those shortest/coldest days, the sun is lowest in the sky and only up for 3 good sun-hours,…and it is coldest, which requires heating the home the most, which uses the most power (more than a/c on even the hottest days). And then you build the racking and array large enough, and face it due-south and tilt it all up at a high slant of about 60 degrees for north america (58 degrees was optimum for their particular latitude). And that will make the most possible power on Dec 21st (winter solstice). If you can make it work on those days, then it will easily be able to provide ALL the power you could ever use, all thru the rest of the year, due to the array being large, and the sun being out SO much longer each day (12 hrs on June 21st, summer solstice!) even with the array then tilted "wrong" for summer.
As we said, they needed ~28kwhrs/day to run their 18kbtu mini split heat pump and everything else in their home, in mid-winter. And so the 11.4kw array will produce a real-word net of ~10,200watts of usable power on a sunny winter day (with the lower temps helping boost production), which, over 3hrs, is a total of 30.6kwhrs. Then we must factor in the inverter loss of 7%, and so their net need of 28kwhrs becomes 29.96kwhrs/day when running thru an inverter. - Just barely provided for, by the 30.6kwhrs of solar production. IF sunny, …which it often is in Sacramento area even in winter, but on cloudy days they have the 64kwhrs of storage to pull from, and can mitigate energy by doing less laundry those days, or even less showers (every hot shower uses about 2.5kwhrs per shower for the heating of water in a conventional electric water heater! Though they plan to replace their water heater soon with a heat-pump style one, which uses one-fourth the energy).
Now, their home is only 360sf., and they needed 531sf of panels to do this, so obviously the array would not fit on their roof. Fortunately they had plenty of land for a ground array, and yet most ppl in suburbs would not have that luxury. But a better insulated home with more efficient appliances (their heat pump is only an EER12.5) like the EER19 heat pumps, and heat-pump style water heaters and dryers that are coming out now, WOULD be able to achieve feasibility with just roof-mounted solar (equaling the square footage of the interior needed to heat), as long as the home was built with solar in mind from the get-go.
The point here is that solar IS already feasible. Systems like this one prove it. They now power their entire home from the sun, with no natural gas, propane, wood, or wood pellets. And by the way, this eliminates the 7 tons of Co2 greenhouse gasses that the average American home emits every single year. We just have to focus on it and begin to seriously implement it, in order to make it a reality,…at least for residential energy uses. I realize many other energy needs are still requiring fossil fuels, like air travel, etc. All the more reason to replace as many things as possible (like residential) with solar,…to leave some fossil fuels available for some of the trickier, energy-intensive needs (as well as all the vital pharmaceuticals and other things we get from fossil fuels).
So the anti-renewables factions can declare that solar panels are just not powerful enough yet, and battery storage is not cheap enough yet, ….but if I can throw together a system for a home with an ROI of just four years, without hardly working at it, then I’d say that they are all wrong, and that solar is here, now, and fully feasible in many circumstances. And so we should all be working toward doing it anytime we can, and doing all we can to enhance the performance and further lower costs and most of all promote legislation which will make it easier and not harder to use solar energy if we want to. The global oil cartel is doing everything in its power to keep solar and wind from becoming more feasible. Spreading their propaganda lies does not help the renewables effort, nor does it help the planet or the working poor that could benefit from solar if it were just made more available.
(note, you'll notice in the pic that they have not built the racking yet, and are going to do that themselves. I just did the electronics/batts in the shed for them and then we wired up the panels and laid them against a hill to test them all out and get them power asap to run their a/c and the rest of the house, and not have to run the blasted genny anymore)(it was already very unseasonably hot there in late June. It's almost as if the climate is changing).
