Tom Connolly wrote:Background: I have been interested in alternative forms of energy since I read Mother Earth's "Homemade Energy Handbook" (or something like that. It doesn't seem to be published any more) in 1977. As I have "grown up" with it and think about living off grid, I become less and less enamored with the idea of having massive piles of batteries around to store energy. What are other ways that electricity from pv panels, wind turbines; and excess heat from combustion or exothermic reactions be stored or used?
Phil Stevens wrote:If you've got a big hill and a sizable reservoir at the top, pumped hydro could make all kinds of sense. I'm not as sold on the stacking of blocks and did the math on a lifted deadweight system a couple of years back...the engineering required to build the supporting frame to lift enough mass to a sufficient height to store 10 kWh was ridiculous when compared to a stack of batteries.
A 1kW motor can winch a 1T mass up 10 m in just over 1.5 minutes (use a block and tackle, please). So you would need 40 tons of mass at a 10 m height to store 1 kWh of energy. A pretty frugal household (way better than mine) might use 10 kWh a day on average. So this means you would need 400 tons of mass lifted to 10 m to store that on a regular basis. Have a think about the sort of structure that you'd need to build to reliably lift and drop that amount of weight. That's where I bailed out.
Kenneth Elwell wrote:Tom, I realize you are looking for off-grid storage ideas, but a net- metered grid-tie gives you the option to store the excess in dollars. Your excess also allows the power station to burn less fuel to fill your neighbor’s needs.
Dollars don’t discharge or leak, and could also be used to buy fuel for a reliable propane generator which could run during an extended outage.
Ryan Sleep wrote:Battary tech has come a long way lithium batteries are fffaaarrrr better then the huge banks of lead acid it also depends on how far your willing to go with off grid everyone seems to think off grid meens a mud house or as i like to call it going full caveman lol but depending on your budget you can go off grid and live with next to no change from on grid living that your use to
The 2 extremes are a 12v set up witch can be done for 500$ to 1000$ and that will power most everything you "need" most 12v are a car batt or 2 but I find that over complicates it for about 350 bucks you can get a 500 watt lithium battery with built-in inverters and everything it's practically Plug and Play it will last longer and is more reliable than let acid
On the other extreem you have large-scale lithium home batteries they cost a small fortune take mine for example a 5kw lithium battery runs about $8,000 after shipping if you would include installation you can add another thousand or so but they will run just about everything just like a normal home the smaller ones might need you just switch things like electric stoves and electric dryers to gas but for the most part your house will operate like normal however there is a bit of a learning curve to figuring out how it all works but the size is not an issue for example my 5 kilowatt battery is the equivalent of about 10 to 12 car batteries however it's actually quite small heavy at 270 pounds with the inverter and solar controller built in and it Bluetooth to my phone but it's quite small I'll even share a picture for you
Tom Connolly wrote:I think every building project - every lifestyle - has to begin with conservation, whether online or off-grid. I don't have a house yet it will be relatively easy to build this kind of thinking into the house.
Tom Connolly wrote:Thanks for a nicely detailed answer. I think every building project - every lifestyle - has to begin with conservation, whether online or off-grid. I have been thinking about all aspects of energy usage: cooking, heating, cleaning, entertainment, working, etc Looking at each aspect to see how it can be done in as efficient way possible and what kind of energy should be used. House lighting, for example, I think should be left as LED's built into the ceiling (or whatever) as the native voltage, rather than upgrading the electricity to 110v after the source and then having the light panel reduce the 110 to 12v (or whatever) to make light. If there are voltage choices for tools, what are they? What is/are the best common denominator for all of this stuff? Is one voltage ok? or maybe 2 or 3?Since I don't have a house yet it will be relatively easy to build this kind of thinking into the house.
Chris Kott wrote:So if space isn't an issue, and it's in a stationary application, the added costs, environmental, social and financial, are unsupportable, in my view.
It doesn't matter what level of permaculture you're after. Permaculture is largely about whole systems design and accounting. There is no waste. If something is produced that needs disposal of, chances are it's not a very permacultural way of dealing with whatever problem you're trying to solve.
If your system produces a waste, its scope is insufficiently large.
Chris Kott wrote:The problem I have with lithium-anything is the lithium. It's expensive because it's rare, so much so that there are places in the world where "conflict lithium" is being mined, destroying the land and the livelihoods of people living there.
It's also unnecessary in a stationary application. One of the major benefits to lithium in batteries is how lightweight the battery remains. This is only relevant if you're talking about a mobile device or vehicle.
As low-tech as lead-acid batteries are, they are infinitely more easily recyclable, and the infrastructure to do so exists today, and has for some time. There are also other stationary battery technologies that will wear longer and be more environmentally friendly than lithium-based technology.
In the context of storing energy, in a conversation that started with hauling many-tonne cement blocks up a cliff with a crane, the benefit of small size and weight matters not at all.
Chris Kott wrote:That's an interesting problem, Travis. We've disincentivised waste by charging for the amount used, and so we've created the drive for efficiency that kills the business.
And yet we rely on electricity. Apart from everyone generating their own, what do we do? State-run, taxpayer-funded public power generation and transmission?
Phil Stevens wrote:@Travis - The quarry makes the proposition viable in your case. How deep is the pit?
Tom Connolly wrote:Someone hinted at this above...I think it is in Arizona somewhere..the electrical utility company raised their rates a blanket $45. Turns out, that is what the expected savings from using solar cells is for the average household. In the past I have read of municipalities discussing the legality/feasibility of installing meters on private wells, which, we all know will end up in the government trying to collect $$$. Our country has a huge amount of money invested in utility infrastructure and there are probably trillions of dollars still outstanding in bonds that were sold to pay for much of it. We can dream and scheme as much as we want and assume that the payback period for our investments to make a greener world will be based only on the "typical" forces but the reality is that someone still has to pay for the bonds and the salaries of the "unenlightened" folk that we put in office.
In addition, even if everyone had PV cells on their homes, the utilities would still have to keep the plants running at 10-20% (or something like that) so that they could quickly be put online again, if needed. You cant just flip a switch and turn those puppies on and off like you would a light bulb. Most of the home setups I have seen look like they were designed for working at full power during the summer months plus or minus months in spring and fall...ideas come and go. but governments will still demand their money and we, the taxpayer/consumer must shoulder the burden.
Phil Stevens wrote:Thermal batteries. Now we're talking. That is something we can implement with low tech requirements. Add in gradient effects and it gets super interesting.