121–130 of 293 posts
As long as EV scale faster than solar/wind we will have little need for storage batteries.
EV are moving in the direction of bidirectional charging and will thus become generator in peak demand period, the grid will become smarter and will offer differential price in function of offer/demand
Earlier quoted context omitted.
It is probably far more cost effective to buy a new air source heatpump. They’re so efficient and work well at low temps now. I have infloor radiant heat at a rural house in upper Midwest, have thought a lot about using solar heat pipes and adding a storage tank, and it’s all so fiddly, pipes and pumps and manifolds and glycol and maintenance, all custom, all expensive. I’m almost certainly better off with PV panels…
Even a modern air source heat pump typically doesn't beat gas for $/kwh. Even in europe where gas prices are sky high, electricity still costs more when you look at the seasonal efficiency of heat pumps, which is typically advertised around 4.4, but various studies show that in most real world scenarios you typically won't reach the quoted lab numbers, so expect to get more like 2.5-3.0. Study: https://www.sciencedir…
the cited paper gives the efficiency of heat pump but we’re missing multiple crucial values to get from there to a comparison of heating costs
Edit: https://great-home.co.uk/air-source-heat-pump-running-costs-...
At current average British prices of 28p for electricity and 7p for gas, and using averages for both it looks like the commenter was mostly correct.
Not 100% if the spf Gives the realistic cop
In a new build that opted to forgo any gas connection, I’d be interested in seeing the costs from the substantial infra savings and hookup savings.
Earlier quoted context omitted.
Using batteries for the grid requires roughly the same amount of batteries as EV’s do. A 100kWh battery pack for a car * 1,000 charge cycles / 25 years = 4,000 kWh of battery per year * ~290 million cars. That’s enough to store almost 1/3 of all current electricity used in the US while ignoring busses and farm equipment etc. Of course actual cost depends on how much storage we need and future battery prices but addin…
As someone that charges lithium batteries for both cars as well as for my house, I can promise you there is 0% of me that wants to cycle my vehicle battery from 100 to 0 every day to arbitrage $1.80 of electricity.
You could also just charge in period of low usage of the grid (if there were special tariffs for that)
Many of the greenhouse Youtube channels I watch do a smaller DIY version of this. They have either dark barrels of water in the greenhouse with the windows facing south to the sun, or a thin metal wall filled with clay and pipes acting as a sun-heat-battery. They pump the water through the barrels or clay battery into pipes that are under ground to store the heat. In winter time they extract the heat from the ground…
Flow batteries are minimally dangerous, have huge storage capacities, have a minimum maintenance per 1000 charge schedule, and while they are slow to "turn on" are faster than geothermal.
Disclaimer; I have a small startengine investment in a Vanadium Flow battery company
The the ratio of area A to volume V for a sphere of radius R is 3/R. The larger the sphere, the less surface area to volume. A corollary of this is that a sufficiently large thermal tank has little in the way of heat loss to its surroundings in relation to its heat capacity. At large enough scale, it's probably the most efficient way to store energy for general heating purposes. Simple water has significant thermal c…
This honestly seem incredibly optimistic to me. Even a high-end thermos will lose its heat in less than a day. Faster in a cold environment. And afaik, temperature loss is proportional to temperature difference, so the hotter the liquid the faster it cools.
Earlier quoted context omitted.
I wonder if it would be possible to scale down pumped hydro to something the size of a tall water tower. Probably not worth it due to the small height difference and volume, and you'd also lose efficiency due to the smaller turbine, but I still do wonder what the actual figures are like for something like that. Especially in cost per kWh stored compared to lithium.
It is 100% possible. The problem is that it's monumentally expensive. You will need to have a pretty big water tower to handle enough energy to run a microwave for a hour. P.E. = mg(h) So say we have 2,000 liters of water that is 50 meters high. 2000kg * 9.81m/s^2 * 50 * 80% efficiency = 784,800.0 joules. Say you have a 1100 watt microwave. A watt is 1 joule per second. That gives you enough energy to run that microw…
Hmm that is an interesting idea, but it would be even more expensive.
If you take that water tower, place it on top of a 80 m hill, then dig down for say another 40 m for the second tank you now have a total of around 160 m of height difference. That would bring it up to 22 households-days or if my conversions are correct, 660kWh, which is not insignificant.
Then again if google is correct the price for an equivalent lithium bank would be only like 100k so it's not even close.
Earlier quoted context omitted.
It is probably far more cost effective to buy a new air source heatpump. They’re so efficient and work well at low temps now. I have infloor radiant heat at a rural house in upper Midwest, have thought a lot about using solar heat pipes and adding a storage tank, and it’s all so fiddly, pipes and pumps and manifolds and glycol and maintenance, all custom, all expensive. I’m almost certainly better off with PV panels…
Even a modern air source heat pump typically doesn't beat gas for $/kwh. Even in europe where gas prices are sky high, electricity still costs more when you look at the seasonal efficiency of heat pumps, which is typically advertised around 4.4, but various studies show that in most real world scenarios you typically won't reach the quoted lab numbers, so expect to get more like 2.5-3.0. Study: https://www.sciencedir…
There should be no economic way that a high efficiency turbine produces and distributes electricity to heat homes at a greater than 1:1 ratio compared to storing, pressurizing, and delivering, then burning in irregularly maintained consumer homes.
Likely the error is that gas pipes to the house are subsidized (albeit the electrical likely is too, with heat pumps and induction stoves, the gas lines are unnecessarily redundant)