We mentioned last time that storage is a key issue in the advance of solar electric power as an energy source. In Connecticut the approved grid-tie system features no storage at all.
There are advantages: the installation is simpler and less expensive. The peak output of the panels coincides with Connecticut Light and Power's peak usage during the business day, lightening the burden on the utility to meet peak demand. The relatively straightforward formula of retail power in, retail power out means that photovoltaic output defrays the cost of incoming power at the same price per unit, so the calculation is made right in your meter and on your bill.
Sadly, there's nothing here for those interested in energy independence. You're still tied to the grid, still paying your bill, still subject to rate hikes and only a tiny junior partner with CL&P in the business of powering the state, or your home. Storage is the problem. Batteries are expensive, heavy, not at all maintenance-free, and not perfectly safe. If accidentally pierced, they stink and the contents are corrosive. Batteries are also not quite in the Star Trek category for capacity. For a bank of four batteries (in series, delivering 48 volts, an efficient output for power inverters) capable of powering your house for 14-16 hours at night, you would pay up to $2000; and forget about operating your electric range or air conditioning. Lights, television, refrigerator, computers is about the limit.
Other storage schemes are worth mentioning: hot water, both domestic and for heating, can be heated by solar electric power and stored. Hydronic panels can also be used for the purpose of charging a hydronic storage bank. Thermal mass built into your house can be used to store heat during the colder seasons, and to store "cold" during summer. More exotic applications like storing energy as compressed air or latent heat in a phase change compound are too expensive and complicated to be interesting to non-engineers.
Battery technology is being advanced rapidly by intrepid science jocks and inventors who want to revoltutionize home storage, hybrid cars and electronic gadgetry, and I wish them well. Beyond lead-acid batteries, Glass matt batteries, Nickel Cadmium, Nickel Metal Hydride and Lithium lie technologies that might put overnight storage within our modest collective reach. And utility companies might soften their stance on hybrid storage-grid systems to allow more off-grid independence.
The cruel catch, that rooftop panels cannot be used when the grid goes down, for safety reasons, is a bitter quibble. Imagine yourself sitting powerless under a roof full of potential, with no way to use the power. That's the current state of the industry. Some accomodation between grid safety and home storage will arrive soon, I hope, and the whole enterprise will begin to make more sense for average people. Simply to partner with the utiliity in producing power and spinning your meter backwards is an idea of some appeal. To achieve emergency backup and the possibility of partial grid independence is a much better reason to hock the ranch and load up your roof with panels. I'm holding out for that.
There are advantages: the installation is simpler and less expensive. The peak output of the panels coincides with Connecticut Light and Power's peak usage during the business day, lightening the burden on the utility to meet peak demand. The relatively straightforward formula of retail power in, retail power out means that photovoltaic output defrays the cost of incoming power at the same price per unit, so the calculation is made right in your meter and on your bill.
Sadly, there's nothing here for those interested in energy independence. You're still tied to the grid, still paying your bill, still subject to rate hikes and only a tiny junior partner with CL&P in the business of powering the state, or your home. Storage is the problem. Batteries are expensive, heavy, not at all maintenance-free, and not perfectly safe. If accidentally pierced, they stink and the contents are corrosive. Batteries are also not quite in the Star Trek category for capacity. For a bank of four batteries (in series, delivering 48 volts, an efficient output for power inverters) capable of powering your house for 14-16 hours at night, you would pay up to $2000; and forget about operating your electric range or air conditioning. Lights, television, refrigerator, computers is about the limit.
Other storage schemes are worth mentioning: hot water, both domestic and for heating, can be heated by solar electric power and stored. Hydronic panels can also be used for the purpose of charging a hydronic storage bank. Thermal mass built into your house can be used to store heat during the colder seasons, and to store "cold" during summer. More exotic applications like storing energy as compressed air or latent heat in a phase change compound are too expensive and complicated to be interesting to non-engineers.
Battery technology is being advanced rapidly by intrepid science jocks and inventors who want to revoltutionize home storage, hybrid cars and electronic gadgetry, and I wish them well. Beyond lead-acid batteries, Glass matt batteries, Nickel Cadmium, Nickel Metal Hydride and Lithium lie technologies that might put overnight storage within our modest collective reach. And utility companies might soften their stance on hybrid storage-grid systems to allow more off-grid independence.
The cruel catch, that rooftop panels cannot be used when the grid goes down, for safety reasons, is a bitter quibble. Imagine yourself sitting powerless under a roof full of potential, with no way to use the power. That's the current state of the industry. Some accomodation between grid safety and home storage will arrive soon, I hope, and the whole enterprise will begin to make more sense for average people. Simply to partner with the utiliity in producing power and spinning your meter backwards is an idea of some appeal. To achieve emergency backup and the possibility of partial grid independence is a much better reason to hock the ranch and load up your roof with panels. I'm holding out for that.
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