The article linked above is a great example of some of the important aspects of getting your own home “off grid capable.”
The article covers two major areas we always advise clients seek to achieve
Additonal topics not covered we want to mention, for future discussion:
All are topics for another day, but back to this article. The person achieving this off grid 30KW plus battery bank system is to be commended for getting it done. But let’s step back just a bit, He is an executive with a solar company, so probably gets his materials “at cost” and a deal on labor, and as the solar executive, he’s probably not struggling to support his family on sub $100k per year. He did mention going to also build a guest house…A 30KW system plus the appropriate scale of batteries, plus installation etc. is somewhere north of a $100k project full tilt retail. We just had a client with 40KW project with inverters and triple 18.5KW battery banks whose solar contract only was $288k. That’s nearly Three Hundred Thousand Dollars, and would be OVER $300K, after the General contractors 17% mark up for overhead and profit. Right. Nice if life allows that. But what about the rest of us. What are us mere mortals left to do?
What If we told you we got our own home to “Annual Net Zero” for electrical usage with a 5.5 KW solar PV system plus a ONE 6.5kw battery bank? And what if the system was about $21k, but since it is financed over 20 years it becomes a monthly payment roughly equal to 90% of our average monthly electrical bill? And our home is a highly inefficient 80 year old drafty leaky old place. How did we do this?
Well part of this is NOT being 100% electric. Because of what’s called the Source Energy Factor. In as simple terms as possible, using remotely generated, utility grid electricity, for heating space or water or cooking is a terrible waste of energy, with a few exceptions. Only about 30% of the original energy makes it to your “point of use” such as a furnace or water heater. It literally takes about 2.8x the amount of “fuel” burned to make HEAT at the utility plant to make electricity (conversion loses) at the utility company, then transport electricity over long distances (transmission losses) at high 480voltage to step it down to low 120v residential voltage, for you to then convert it back to heat (more conversion losses) to heat your home living space or water for washing, or for cooking. So at our home, space heating and water heating are with locally stored fuels, mostly Kerosene, but our dryer is propane. Our home in Oregon was heated 100% with wood for 6 years, at less than 10% the cost of using electricity, so adding a wood stove at our current home is the next project we have slated to achieve. Ditto for a wood fired boiler. Above I mention “a few exceptions”. We do have an induction cooktop and a 600 watt convection oven microwave. Note, we cook with a 600 watt oven. They typical electric range/oven is a 2,000 watt heating element. With that 2,000 watts it take 2-hour to bake a full large chicken dinner or 4KwH (2,000watts = 2kw, times 2 hours = 4KwH)Our 600 watt convection oven/microwave does the job in about 1 hour, but lets say is 1.6 hours. Or 1KHW (600W = .6kw times 1.66 hours= 1 kwh)The convention oven microwave is basically 4x more energy efficient than a typical “resistance” type electric oven. Electric dryers are even worse at using energy efficiently, hence the propane dryer. We don’t even own it. It’s a brand new, latest model, but a $20 per month lease from the propane supplier, and if it breaks they replace it. And the induction cooktop is so fast its remarkable, (faster to boil water than the microwave) and feature loaded, like setting timers for each burner so you don’t have to watch pots as diligently, that as much as Gas might be a slight energy savings, the modern tech of induction cooking has won over our family, YMMV.
In our case, the out of pocket to get our solar up and running and getting off electric for heat related tasks was very low budget. We did buy a $3k top efficiency kerosene (or home heating oil fired) tankless point of use water heater, and we upgraded to the latest generation of induction cooktop ($1,100) and convection oven ($500) for a total of $4,600. But the solar and propane dryer are on the pay as you go plan and the other item $4,600 could have been financed on an equity loan for less than $50 per month if one did not have the cash.