Hakan, I have done some superficial research, and my preliminary conclusion is that scale is the determining factor. For household-scale energy storage, batteries are the most economic solution for storing electricity. I did some rough calculations, and concluded that with realistic time-of-use pricing (low off-peak - about Cdn$0.03/kWh and high peak prices - about Cdn$0.20/kWh - reflecting hourly market rates - generation, transmission and distribution costs only), then having a day's worth of storage capacity could pay back in my situation - assuming lead-acid golf- cart batteries having a life of five years or more in this application, conventional charger, and inverter was already in place for other reasons (UPS or capturing solar or wind-generated energy).
I put in the battery bank when we were promised by our politicians that the time-of- use option was coming. Of course, it never happened. Now, I stock it with batteries that are no longer of sufficient capacity to power EVs, but still have some usable capacity, and only use it as stand-by power when the grid goes away (like last August). At larger scales, if the space is available, pumped storage appears to be the technology of choice for electrical utilities. In specific circumstances, there are other technologies that may be attractive - e.g. composite (super) flywheels Some other household "storage" options include setback thermostats on electric water heaters (so they go to a higher temp at off-peak times, e.g. 60 C, and lower at peak times, e.g. 50 C - that way the water heater will not turn on during peak periods if no water is used). Similarly, "storing" heat and "coolth" in thermal mass during off-peak periods (notably if heat pumps/air conditioners are being used). I have also heard of people putting their refrigerators and freezers on timers so their compressors only run during off-peak periods. There is also time- shifting; running specific appliances (e.g. washing machine, dishwasher) at off- peak times. And of course, my personal favourite - EVs - battery storage on wheels. Darryl McMahon Hakan Falk <[EMAIL PROTECTED]> wrote: > I am preparing an article about general energy storages and wonder if > anyone have calculated the costs for the battery storage part of small > energy generation. The more I look at this, the more possibilities opens > up, by using storage techniques. It is even more interesting when you look > at combinations with renewable energy sources and heat pumps of different > kinds. This especially in countries with high electricity costs, like the > European ones. > > The reason why I ask, is to know what could be gained by only a storage > solution, by utilizing rate differences. If you have low rate prices, they > are normally 50-60% lower than normal rates. With a battery storage > solution, would it be feasible to charge during discounted time and that > way reduce over all electricity costs? > > Hakan > Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://infoarchive.net/sgroup/biofuel/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/biofuel/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
