In another article, I went through what I learned from buying a house with limited electrical service. Long story short, the status quo of getting energy from natural gas, water service, and even sewer service is baked into many if not most homes, and it’s hard for the owner (and harder for a renter) to get out of that rut. It’s even harder if one’s home is only wired for 50 amps, like an RV.
The obvious thing to do to reduce impacts is to improve the electrical service, add solar+storage, and convert all appliances to electric. This would have the advantage of making the whole house solar-powered, and also make it more resilient to power shortages and disasters. That’s something we frequently write about at CleanTechnica, and it’s something that Tesla offers, so some of us are very motivated for various reasons to promote that.
But then again, both my wallet and the environment would be better served if I didn’t need as big of a solar system and electrical service, but only if that doesn’t mean I use more “natural” gas. In other words, conservation needs to be part of the equation. Electrifying everything is great, but lowering those electrical needs is even better.
In this article, I want to explore some of the solutions I’ve come across while looking for ways to need less of all kinds of energy in my household.
This is a big area where every household uses energy, so it makes sense to start there and find ways to whittle down.
If I want to put 100 amps into my house, still have 50 amps for future EV charging needs, and a few other amps for a small shed/workshop and outdoor outlets, I’m in for upgrading to a 200-amp electrical service. That means I’d be doubling my potential electrical usage. Sure, that’s better than burning natural gas for home appliances and gasoline for transportation, but that’s still a lot of potential impact.
As I mentioned in my other article, I can pull up to 100 amps from the electric company before there’d be any problems there, so it would be a whole lot easier, cheaper, and more convenient to keep it all under 100 amps.
To see if that was feasible, I had to challenge an assumption I had about EV charging. In the past, I figured I’d want to be able to charge 2 EVs in the driveway, and the most power hungry level 2 EVs (other than older dual-charger Teslas and a few outliers) pull 7.2–7.7 kW at maximum, but no matter how much the EV could take, it could still charge great on fewer than 50 amps. If I had a 50-amp circuit, I could charge one EV at maximum speed, or use a power sharing EVSE to charge two EVs at 20 amps simultaneously.
So it appeared that was what I needed, a 50 amp circuit (or greater).
But then I took an honest appraisal of my charging situation. My 2018 LEAF charges at around 24 amps at home (just over 6 kilowatts), and that means it can go from dead to 98% in about 6.5 hours. It’ll sit and balance cells for another hour, but that can be skipped if I’m in a hurry, because that last 2 percent doesn’t make a big difference on any local trips. If I charge the thing when I get home in the evening after running errands and have a nearly dead battery, the car has at least 11 hours to charge before I need to take kids to school.
Even charging at 16 amps (3.8 kW), my LEAF would go from dead to full in under ten hours, and most days I’m nowhere near empty anyway. So, a 20-amp circuit is really enough as long as I get an appropriate EVSE that limits charging to 16 amps. Then, I can upgrade wires going to the house and put an 80-amp breaker on that circuit, which is plenty as long as we don’t run the dryer at the same time as an electric oven.
I also don’t think I’ll need a big EV charging circuit in the future, either. I’m going to keep the LEAF long after it’s paid off and use it for mom-taxi duty (kids to school, etc). I’m getting an Aptera next year for times it’s just me or me and my wife driving (which happens quite a bit). The Aptera will usually charge on its built-in solar panels, but occasional level 1 or 2 charging may be needed. 16 amp charging would add 38 miles per hour to an Aptera, and would add 380 miles overnight, which is all the range most EVs come with (the Aptera will have 1000 total).
If an electric RV comes out, I may reconsider, but for now, I see no need for all of the extra power.
Heating & Cooling
Another big energy user is heating and cooling. On this front, I’m considering experimenting with geothermal energy mixed with direct solar air heating and some sort of thermal mass battery. In other words, there are other choices beyond fossil fuels and electricity worthy of consideration.
Before I looked into it, I thought geothermal energy was something that only happened on an industrial scale using deep, deep, deep holes in the ground that some sort of energy-absorbing fluid got pumped through. I also knew that if one had a lot of land and reasonably damp soil (I have neither), that you could use the earth as a heat exchanger for a heat pump. What I didn’t know was that one could do what was done anciently in Southwest Asia and simply push air through pipes or tubes in the ground to cool it to around 50 degrees Fahrenheit. This type of air conditioning can work well by convection and a solar chimney in “earthship” houses, but for my purposes the whole idea is just to make the electric air conditioning turn on less.
It’s also possible to build simple boxes that heat up air using sunlight directly, without generating electricity first. This would work well where I live because we get many cold winter days with plenty of sun, but wouldn’t do very well for night-time or for locations that get a lot of clouds.
There are also a number of DIY projects floating around the internet that store thermal energy from the daylight hours and use it during the night. There are a broad variety of ways to do this, including everything from big piles of dirt, hot water tanks, transparent tubes that sit in the sun near a large window, or just barrels of water to stabilize a greenhouse and prevent overnight freezing. Some of these systems are active, while others are passive, but there are many cheap options.
But Can This Really Make A House Use Less Electricity?
That’s the real question, and it depends on one’s situation and what they do. Earthship builders have had great experience using no electricity at all, so it seems possible for a more conventional home to at least use less electricity. Just getting it to the point where gas isn’t needed would be enough for me.
Featured image by Aptera