Douglas Hvistendahl

Another Reality Check for Energy Storage Investors

Has anyone considered what lower storage costs will do for backup systems? We are digging out from a foot of snow. The electricity held up, but if it had been an ice storm? In this climate it makes sense to have multiple redundant heating sources, and we have made certain that 20% of them don't need electricity. Many have not taken this precaution. There are going to be many uses for a less expensive backup system. Keeping the control electricity for the furnace working is only one of them.

Most people only think of backup with computers, but there are many other critical systems, even if they are not as valuable.

A Very Smart Plan for Federal Smart Grid Grants

Part of yesterday (4/22) was spent at a sales push for an auto dealership that moved. Many standard and some hybrid cars around the lot, but also two neighborhood electric vehicles at the main entrance, one of which was gone by the time I left. They know about the new solar roofed NEV also, but it was too new to get for the bash. Given our NDak climate, the choice here is for enclosed, and/or open but not in the winter, please, types. Looking forward to the upgrade (hybridization) kits for low mileage vehicles myself. Like peak oil, PV grid parity is close enough to be argued. But PV boosting of vehicle energy is not! Keep us up to date on the PbC batteries, please.

Lithium-ion Batteries: 9 Years of Price Stagnation

Keep one eye on MDI and the Flow-aire technology. No one else has a small compressed air storage so close to mass production. It will either flunk or be a rule-breaker.

BTW, a backup flywheel MFG company, ACPW, has a CleanSource (tm) design that uses flywheels for the first short bit of a power down, and backs it up with CAES using micro turbines. Not practical for transportation, but the cool air coming out of it replaces the air conditioning when a data center is being powered from this storage source. This gives 2/1 results.

Cleantech, Optimism Squared and the Battery Industry

In the long run, near isothermal super-compressed air is likely to pay off. However this is not for anyone who wants quick results - it is as speculative as Axion. Glad to hear that some deployment is going on now. However, while in the long run we will have a wining technology, short term is going to be a multitude of technologies!

Long Live the Cleantech Revolution

A note on Active Power: One of the reasons they are concentrating on back-ups is their cool-source design. They store compressed air over a long period of time; the quick changes are handled by flywheels, but a long outage draws on the compressed air, producing as a byproduct, cooling to take the place of the energy-using air conditioners. I'd like to see what could happen by combining their low-speed flywheels with a more efficient air storage, such as MDI's triple-expansion & heat transfer design!

Smart Grid's Enabler - Alternative Energy Storage

On Feb 09 02:35 PM Redwood_1 wrote:

>compressed
> air is in any way an efficient storage mechanism. From a mechanical
> standpoint, it's an incredibly lossy process, and one subject to

Depends on your mechanism. Isentropic compression wastes energy heating the air. Isentropic compression wastes energy cooling it. 95% isothermal is available for stationary applications. A 95% isothermal compression&expans... would be 90% efficient! The equipment is more expensive and complex, which is why almost all uses are isentropic. Maintenance needs depend on the mechanism also - the standard designs are cheap, but wear poorly. Isothermal C&E scales up very well.