3 ms·

I agree that high energy consumption is a problem, but this analysis is overly pessimistic because you're not factoring in the fact that the system is rechargin

by gh02t 8y ago

I agree that high energy consumption is a problem, but this analysis is overly pessimistic because you're not factoring in the fact that the system is recharging during the day. As long as the average load is lower than your average power draw you can sustain it indefinitely. The battery capacity only needs to be there to compensate for your worst case scenario of bad weather/reduced light exposure. So maybe not surviving a nuclear apocalypse kind of scenario, but otherwise workable. Also, a 100 watt LED "bulb" is ridiculously bright. That's far more light than you'd get out of a tungsten bulb, 200 W of LEDs is [more than] enough to light an entire house. Electric heating and cooling is the real problem when it comes to energy consumption.

imtringued 8y ago
There is also the assumption that you use all lamps/electric devices for 24 hours every single day. But humans tend to sleep and the sun is shining during the day so you end up using your lamps for only 8 hours or even less per day.
snowwindwaves 8y ago
In a lot of places blackouts or grid failures tend to coincide with bad weather that doesn't supply much solar charging. The bad weather is quite often windy though so a small wind turbine to diversify the generation sources is helpful. Living off of solar and batteries means foregoing things like the toaster and the blender.
- gh02t 8y ago
  True, which is why your battery needs to be large enough to supply power during your worst-case scenario for bad weather (or have back up systems like wind/thermal like you mention). You also definitely want a plan for cutting consumption to only essentials during such a blackout. A toaster / blender really doesn't take that much energy; sure they're 500 W or so, but you don't typically operate them for long periods of time. The majority of energy usage in most homes is devoted to heating and cooling, which are high power and run for long periods of time. My point was that it's important to distinguish that long blackouts with severe inclement weather are extreme events, and on average a solar power system should be fairly stable as long as your usage is kept to essentials. I completely agree with OP that you really do have to cut back on power-hungry luxuries for solar-only to be really viable, but you should be able to at least keep the lights on for quite a while. In terms of holding out during more extreme events, yes... relying on any single energy source leaves you vulnerable in that respect.
  - snowwindwaves 8y ago
    Here's a video of a family that lives off grid you might find interesting https://www.youtube.com/watch?v=v8Pe_u_4q5M https://www.youtube.com/watch?v=v8Pe_u_4q5M

by gh02t 8y ago

imtringued 8y ago

There is also the assumption that you use all lamps/electric devices for 24 hours every single day. But humans tend to sleep and the sun is shining during the day so you end up using your lamps for only 8 hours or even less per day.

snowwindwaves 8y ago

In a lot of places blackouts or grid failures tend to coincide with bad weather that doesn't supply much solar charging. The bad weather is quite often windy though so a small wind turbine to diversify the generation sources is helpful. Living off of solar and batteries means foregoing things like the toaster and the blender.

gh02t 8y ago
True, which is why your battery needs to be large enough to supply power during your worst-case scenario for bad weather (or have back up systems like wind/thermal like you mention). You also definitely want a plan for cutting consumption to only essentials during such a blackout. A toaster / blender really doesn't take that much energy; sure they're 500 W or so, but you don't typically operate them for long periods of time. The majority of energy usage in most homes is devoted to heating and cooling, which are high power and run for long periods of time. My point was that it's important to distinguish that long blackouts with severe inclement weather are extreme events, and on average a solar power system should be fairly stable as long as your usage is kept to essentials. I completely agree with OP that you really do have to cut back on power-hungry luxuries for solar-only to be really viable, but you should be able to at least keep the lights on for quite a while. In terms of holding out during more extreme events, yes... relying on any single energy source leaves you vulnerable in that respect.
- snowwindwaves 8y ago
  Here's a video of a family that lives off grid you might find interesting https://www.youtube.com/watch?v=v8Pe_u_4q5M https://www.youtube.com/watch?v=v8Pe_u_4q5M