So dimensions of the question go like this:
- It is often something like $10k to $20k to create a new grid connection for a rural property. Wouldn't it be nice to put that money towards electricity storage or on-site generation/both?
- Sometimes there is a microFIT project involved - so if we are going to sell solar electricity to the grid, then we need the grid connection anyways
- Electric vehicle - If we are going to have an electric vehicle, then we are no longer purchasing gasoline, but must instead supply additional electrical energy to our vehicles as well as our house - well, do the math and you'll probably find that net zero may often be practical for our houses, but net zero including our transportation? - that can be quite an additional load, depending on how much one travels, or plans to. While the vehicle can act as a big battery for the onsite storage of electricity, everytime I look at vehicles storing energy for the house, I come up short - either for the house, or for the vehicle - so in terms of timing, this option has yet to prove viable.
- Microgrid stability - In one project, there is kind of a significant computer activity in the house. This owner is looking seriously at back-up generation, but one also needs a transition system - like a battery bank or an ultracapacitor bank - basically a UPS that gives the generator the few seconds needed to come online in a black-out. This house is also in a valley, so the back-up generator will be perfect to run pumps for flood protection - Even though we are in a big city, power outages frequently come when there are big rains.
If we need back-up-generation AND the grid connection is costly, why not forego the grid connection altogether?
- Finances: In one instance, the bank decided what to do, rather than the buyer of the land - The bank's position was this: Build all services - septic, water, and grid connection, or we won't lend you the money to buy the land. - Sheesh! They must not have heard of solar PV!
This question always fascinates me - I get to go out looking for off-grid technologies. So today I came across this on Gizmag:
http://www.gizmag.com/power-pallet-20-gasifier-biomass-generator/32245/ - the power pallet. This is a machine which eats biomass, and makes heat and electricity, and it is smallish - relative to many biomass machines. it produces about 20kW, and costs about $30,000. Kind of attractive if a grid connection costs $15k and back-up generator $10k.