“Given the current costs of generating and storing power at home, even residents of sunny Arizona would not have much economic incentive to leave the electric-power system completelyâ€”full grid-defection, as McKinsey refers to itâ€”until around 2028. But partial defection, where some homeowners generate and store 80% to 90% of their electricity on site and use the grid only as a backup, makes economic sense as early as 2020.”
See Batteries and solar panels threaten to turn the electrical grid into a giant backup system, upending the utility industry’s business modelThe current price of hardware for home solar generation is OK for those buying or building a home. It would be just a tiny slice added to the mortgage. It’s those who pay out of pocket who recoil from the sticker price. It’s ~$1/watt for solar panels, a few $K for an inverter, and a few $K for installation. Also, it’s a few days of disruption/construction around the home. Also, TLW isn’t ready to have solar anything conspicuously decorating her home…
I, OTOH, relish going solar even in part and plan to set up a small system of just a few KW to run my new Solo EV. It makes sense, particularly if I get to drive as much as I want and TLW will never see it on the utility bill… Chuckle.
My plan is this, making a picnic table out beyond the garden with a solar panel shade pivoting above it. Being a welder, I can make a frame allowing the panels to follow Sun and shade the table all day long. Cool, eh? It’s pretty easy except one has to anchor it really well against the wind. I need a substantial concrete/stone foundation, a sturdy post with a hub pointing to the North Star, a mechanism to adjust elevation according to the season and a mechanism to rotate the panels keeping them always pointed to Sun. It’s a bit of work, but I’m retired and enjoy making stuff.
Each 1x2m panel makes ~300W in full sunlight, so it would take 11 or so to charge Solo at 240V. I can lighten the burden on panels by using a battery to accumulate energy all day long and deliver it through an inverter for charging Solo. 4 panels could refill Solo completely in a day but 6 would be more sure. I could stack them in a 1-2-2-1 pattern to approximate a circular solar shade for the table. The battery is expensive because it’s so heavy and requires freight from China for NiFe types. Cells in the range of 100-400 Ampere-hours store 120-480 W-h and Solo needs 16.1kWh nominally, so 40 cells, one crate, deliver 4.8-19.2 kWh. On average, Solo will likely need only 4kWh to top up or would need to drain the smaller battery multiple times or the larger battery once for a full charge. It’s doable.
In a 25 year lifetime for solar panels, this system would recover many $thousands of solar energy easily paying for the whole investment. If I drove my Solo hard, say 32000 km per annum and charged only at home, that would be 200 full charges, 3200kWh, $320 worth of electricity per annum. Over 25 years that’s $8000 worth of electricity from 4-6 panels costing $500 each, so the system pays for itself sooner or later. The hardware and mounting I would build will last indefinitely, so that cost could be spread over a lifetime. I like the numbers. I will dip into my pension next year to pay for the car and the charging system. TLW won’t mind because she’ll want a Solo too, and a shady spot to sit in the back yard.