Some will no doubt wonder why solar, wind, and micro-hydro power are not discussed in the off-grid-capable power series until the fourth part, and as an advanced topic. The truth of the matter is, these forms of power, although potentially great, are not within the reach of the average homeowner seeking to make their home off-grid-capable. As with Parts 1-3, Part 4 seeks to add on build upon the previous steps with additional capabilities and redundancies.
Powering an average home with solar, wind, or micro-hydro power would usually be an expensive proposition. The costs per kWh of power (the same unit of measure your power bill uses when billing) is often 5-20x more than grid power with these alternative energy sources. This is one reason it makes sense to be off-grid-capable, and not just off-grid! We’re saying this as folks who own and use solar, not as some solar haters.
For those building an off-grid-capable home from the ground up, alternative energy sources can provide a significant portion of the home’s power, assuming the home is designed around such. That might include above-average insulation, designing for passive solar heat, using the earth to heat and cool the structure, DC lighting, DC appliances, etc. Retrofitting an average home to these standards would be prohibitively expensive.
In the context of off-grid-capable power for the average homeowner, Alternative energy systems will basically serve as fuel extenders in an otherwise generator-based system. Read that again, and understand what is being said. This may come as a disappointment to many but is the reality most will face unless significant resources are available.
By now you should already know what your energy needs are – at least for your critical loads. To confirm our assertions about the expense of such systems, spend some time looking for solar, wind, or micro-hydro systems that produce the power necessary for your critical loads. Before you do, make sure you understand a few things:
- The solar Insolation for your area (how many sun hours are available per day)
- You will need to harvest all the energy for the days’ energy in those few short hours
- The peak usage of power for most households are in non-daylight hours.
- This means you’ll need enough storage (batteries) to house all the solar energy harvested during the daylight hours (if it was a sunny day).
- If you want to be able to handle cloudy days, you’ll need to multiply your battery capacity by the number of days you want to be able to function without sunlight.
- You can’t discharge most batteries entirely, so whatever your storage needs are, you’ll need about 2x that number in battery capacity.
- This much battery power represents several tons (literally) of battery, so be sure to have some space ready, and some strong backs to move them (or a forklift)
If you take the time to investigate the above, you’ll soon discover that you will need literally tons of batteries to store energy and a large amount of solar equipment to capture this much energy – all to avoid a generator?
All is not lost! Every kWh you can produce with solar, wind, micro-hydro power is less time your generator will need to run and less fuel to burn. Alternative energy sources have a place in the off-grid-capable home. It’s just important to have a realistic view of what that place is.
If you have a generator that can provide you with off-grid-capable power – consider if the investment into alternative energy sources is worth it. There are many good reasons to move forward with such.
- Fuel savings
- Whole-house battery backup (assuming a battery-based system is used)