Part of why I opted for solar was that I believe strongly in minimizing my impact where I can. By putting a power supply on my property I not only have some degree of self-sufficiency (in terms of knowing I am generating the power I am generally using – though with the traditional grid-tie system I am still subject to the system being shut off if power goes out in the area), but I also cut down the transmission distances (and associated losses) involved in transporting power from a distant generating facility to my home. This is the case both for my own use, as well as for the homes around me where most of any power I put back in the grid is consumed during the day. Against this background it is probably unsurprising that by having my own supply of household electricity Some of my habits have changed to bias toward electric usage rather than other energy sources. Here is a rundown:
1) Heating and cooling: Not a huge change here, as the costs involved in switching from a propane heating and hot water system to an electric system is a bit higher than I really desired to jump into. In addition, that would greatly increase my electric usage to the point where the installed system (which was limited to 100% of my prior 12 months average monthly usage – and I had been in a highly efficient mode at that period) would be insufficient to provide coverage. The one change I did make was to design and implement an independent fan and water control system for my swamp cooler so I could take advantage of the cool night air by running the fan longer without water in order to cold-soak the house overnight.
2) Cooking: This is where the big changes happened. I have a very large and very nice propane stove. Replacing it with an electric model was not an option on cost and performance reasons, but I found other ways to switch usage and provide improved capabilities at the same time. I bought an electric pressure cooker, a sous-vide immersion heater, and a convective toaster oven. During the summer I can put these outside and not only use my solar power to effectively cook a meal, I can also reduced the internal heat load for the house and need less cooling. In the winter I can use them inside and the associated heat losses with smaller appliances assist with heating the house. All 3 systems work very well within my cooking activities, and a side benefit of the toaster oven is that for many things I can use it with as good results as the large oven but without having to heat up as large of a volume. In addition, I invested in a large chest freezer to enable more effective storage of many foods as well as saving leftovers from when do cook a large quantity of something.
3) Cleaning: A small electric blower is the best device by far for clearing off a tile patio in the desert, and an impulse purchase of a robotic vacuum has made a huge difference in the overall cleanliness of the house by keeping the daily buildup of dust at bay. Neither of these are huge changes in and of themselves, but they make things easier and more effective so I do them where before I couldn’t be bothered most of the time.
4) Entertainment / Office productivity: I am not as opposed as I used to be about adding more electrical equipment in these areas. I’ve run additional powered speakers to other areas of the house, and I went from a single screen to a 3 screen computer display setup which has been a big productivity boost when I am working on more complicated projects. I also added additional lighting in my workshop and dug out an old electric space heater I hadn’t used in years so it is far more comfortable to work in the (unconditioned / uninsulated) shop during the colder parts of the year. When it warms up in a few months I will probably be adding a portable swamp cooler for a similar reason.
Those are the major changes, and they have led to a slight increase in overall electrical usage to the point where my installed 2.7 kW system was no longer at 100% of my usage. When I had a followup conversation with the company that installed my solar array I mentioned this, and they pointed out that in the terms of my PTO letter from the utility was a clause that after the system was installed I could add up to 1 kW additional capacity without requiring a new agreement.
We ran the numbers, and it came out that that was a reasonable and cost effective option, particularly as I had sized the original inverter to accommodate future expansion up to 5 kW. A few weeks later they had completed all the required paperwork and permissions needed to do so, and a few days ago 4 additional panels showed up on my roof. Initial indications are that, given the relatively small size of the original array and by operating closer to the inverter design point I’m seeing about a 40-45% increase in system capacity.