Best ways to store power

[Chris]

[Chris]

[Bob Boyce]

Probably the most efficient energy storage with current technology would be super or ultra capacitors, but they are not yet very affordable.

You're absolutely right about batteries. Besides not being real efficient, they are about the lowest cost thing going. Even at that they are expensive to buy and require frequent maintenance. There are huge batteries available that if properly cared for are designed to last for 25-30 years, but they are very large and weigh thousands of pounds.

Water storage is how some of the larger utilities do it. They pump water up to a reservoir during times of surplus energy, then reverse the process during peak demand periods, with most using the pump as a generator. Not too many of us could afford that type of operation, and the overall efficiency is very low. There are a lot of losses in both the pumping and generation phases.

Too bad fuel cells aren't more efficient. Generating and storing hydrogen under high pressure is pretty easy. Getting energy back out of stored hydrogen is a different matter. For conventional parahydrogen (H2), which is what stored hydrogen would become after the orthohydrogen decays, burning in an internal combustion engine averages about 20% efficiency. Lower cost fuel cell efficiencies are typically around 35%. If one is wealthy enough to buy exotics, they are usually around 55% or so.

I like the flywheel idea. Spin up a massive weight with surplus energy, then use that stored energy to generate when needed. Motors and generators can be built much more efficient than many other methods of energy storage. Let inertia be our storage medium.

Bob

[Bob Boyce]

I had an idea that falls (no pun intended) along the water storage idea. Instead of pumping water, how about lifting a massive weight with a steel cable on a spool and let gravity be the storage medium. Use a gearbox with an efficient electric motor which can double as the generator. Just clutch a brake on the motor to hold the weight up until power is needed, then let gravity do its thing

Bob

[adam666]

Hi,

Im kinda leaning towards the Hydrogen and Methane solutions.

how long can hydrogen be stored before the orthohydrogen decays?

cheers
Adam

[Bob Boyce]

The decay time depends on the percentage of orthohydrogen present, along with the temparature and pressure it is stored at.

Something I forgot to comment on was about using utility intertie. While some states have laws in place to force utilities to accept net metering of surplus power generation from home producers, most utilites have regulations on their side that allow them to place extremely restrictive requirements that make it prohibitively expensive for the average home power producer to comply.

Where I live, there are no laws forcing the utility to allow net metering, but there are similar laws to that effect in the state that the utility is located. In order to discourage net metering, the utility has a list of requirements.

1. They require the site to have every aspect of the installation performed by one of their listed approved licensed electrical engineers.
2. They require that all equiptment used at the installation be on their list of approved equiptment. This includes your choice of brands and models of solar panels, windmills, hydroelectric equiptment, and inverters.
3. They require quarterly inspections to ensure that the site continues to meet utility power generation regulations, and that only approved equiptment is in continued use.
4. They require 2 electric meters, one to meter power consumed and the other to meter power generated.
5. They require you to pay retail for power consumed, while they only pay wholesale for power generated.
6. You must sign a 5 year contract that gives them full control over the maintenance schedule of your installation at your expense.

In order to eliminate "gorilla power" (unregistered/illegal grid intertie systems), they have installed electronic meters in all customer locations that report meter revolution counts at regular intervals to a computer at their office.

I'm hoping that the state I'm in passes a much fairer net metering law than that. The utilities have been fighting the state for over 15 years already. The utilities have been shooting down every proposal, so it may never come to pass.

Bob

[Chris]

[Bob Boyce]

[adam666]

[adam666]

[Chris]

[adam666]

Id been thinking bout a solar h2 compressor

having say: 2 black colored vessels filled to say electrolyser pressure, they are then heated in the sun and once at a peak, can be transferred to another vessel for high pressure storage.

sorry I dont have any numbers / temps for evaluating but if memory serves the h2 pressure increases quite rapidly as heat is applied.

sure its not 1000psi but you wouldnt need to buy a compressor

nb vessels may in fact need to be say: hydride containers? safer for holding h2 during heating process?

cheers
Adam

[adam666]

cool article here on solar hydrogen/electrical storage using ZINC





powder form sounds like a great (read: safe) way to store copious amounts of energy

[skibum13]

I think the big weight idea is really interesting. I don't think you would need to live on the side of a cliff and have 5-ton pieces of metal suspended off the edge (although that would look pretty damn cool). If you had the gearing right, you could have a much heavier object and only lift it maybe 10 or 20 feet off the ground. If you had a big metal tank (several thousand gallons) and filled it with water, that would definitely weigh quite a bit. If you had a gearing ratio low enough that it could easily be turned by an alternator-type motor, you would have the potential for a lot of energy storage. Granted I'm talking about a permenant installation involving a steel i-beam structure that can support tens of thousands of pounds, but scrap steel is fairly cheap and a welder isn't that expensive either. The hardest part would be getting a gear ratio that is big enough and can support that amount of weight. You could also use a pulley system to reduce the pressure applied directly to the gear-box.

I know you could use the same alternator to generate power, but I couldn't think of a way to keep the weight from lowering too quickly and spinning the alternator faster than is necessary.

[kevinsatterfield]

since "raiders of the lost arc " i have wanted to capture a lightning bolt and store that energy or just part of it.sound too crazy?