Based on my loan, my current cost of energy is much lower than if I bought it from the grid. (About 4-5 cents per kwh, instead of 20 cents per kwh.)
My monthly payment never goes up, but it's unlikely that my cost of grid electricity will fall below 4-5 cents per kwh during the lifetime of my loan.
Remember, the cost we pay for electricity includes the cost to run and maintain the grid between the generator (or battery) and our homes. The system in the article is a little more than 3 seconds per kwh BEFORE the costs of the grid are involved.
Wow, what was your price per W? At ~$2.5/W before tax breaks, and a 5% yearly discounting rate, I calculated my TCO was about $0.08/KWh after tax breaks using a spreadsheet to calculate the net present value of the future electricity.
Usually the salesmen will quote you a cost per KWh based on the total energy generated over 25 years divided by the cost of the system. This is usually very far off (in their favor) for two reasons:
- Time discounting: at a generous 5%/year, discounting makes electricity in 20 years only worth 37.6% as much as electricity now.
- Risk: presumably, future increases in panel efficiency and manufacturing techniques will make electricity even cheaper than it is now. By signing a contract or buying a system, you're buying future electricity flows without knowing how much they'll be worth yet.
Based on my loan, my current cost of energy is much lower than if I bought it from the grid. (About 4-5 cents per kwh, instead of 20 cents per kwh.)
My monthly payment never goes up, but it's unlikely that my cost of grid electricity will fall below 4-5 cents per kwh during the lifetime of my loan.
Remember, the cost we pay for electricity includes the cost to run and maintain the grid between the generator (or battery) and our homes. The system in the article is a little more than 3 seconds per kwh BEFORE the costs of the grid are involved.