To build robustness requires two things:
- A method of generating electricity (such as solar pv panels)
- A way of storing energy so it can be used when electricity generation is not possible (night time for solar pv panels or when the wind isn't blowing for wind turbines).
With subsidies in most countries there is a return today on solar electricity generation using reliable well established technology. Companies and households could switch to solar today and save money. Note: Do bear in mind if everyone did it then the subsidy system would collapse. Future advances in solar technology will hopefully bring down the costs of installing solar panels and the subsidies required.)
Battery storage is less developed and is likely to be the next big thing in energy. It could transform solar/wind power use so that off-grid systems are possible for companies and households.
To make battery storage viable will require some progress on battery technology to make it suitable for the average house. In the US the average property uses about 32kWh of electricity per day. In Europe it's around half that amount at 16kWh, partly due to the way homes are heated in Europe.
If we take the lower European figure and assume we want energy security for at least 10 days i.e. assuming that the battery storage can provide the house with enough electricity to survive a loss of generation capacity for 10 days, then we need 160kWh of stored electricity.
A mid-sized car battery stores around 70 Amp hours of electricity at 12 Volt supply. So to convert this into kWh we multipy 70 x 12 and divide by 1000 and come up with 0.84kWh of energy stored in one lead acid car battery. SO to cover the power needs we would need 160/0.84 = around 190 car batteries. With an average cost of say $120 per battery this would cost around $22,900 and would occupy quite a space in the average home as well.
Now there are probably better ways of achieving this level of storage, such as fuel cells but it gives a guide to what is possible off the shelf today. If you were on grid and wanted say a day's protection then the cost of battery storage would fall to $2,290. Still quite an investment for very limited system robustness.
I will start to get really excited when the costs fall to around 10% of their current level as this is the day when we maybe won't need energy companies at all as we all have our own local power generation systems. When will this happen? Well not anytime soon but I can see a world in 20 years time where this is becoming a possibility.
In the meantime for those interested read more about solar pv panels for domestic electricity generation.