5 ms·
This is great technology, simple and effective. I’ve spent many hours reverse engineering to see how effective and expensive it might be. I’ve found it’s very c
by gorpy7 3y ago
This is great technology, simple and effective. I’ve spent many hours reverse engineering to see how effective and expensive it might be. I’ve found it’s very cost effective but heat can be hard to calculate. i like that they did a prototype. i think i’ll do one at some point. for an individual house it makes more sense to improve my insulation but i think ill still build a small version for fun.
- dragontamer 3y agoIceBear went out of business with the opposite tech: tanks of water storing the cold generated from excess AC cycles. Cheap electricity can make cold, and then a fan can convert the cold water into cold air during peak hours when electricity was costlier. Fans still took electricity to run, but it'd only be a few hundred watts to run air-conditioning rather than kilowatts of power.
- 0cf8612b2e1e 3y agoHow long ago was this? The idea seems simple enough and would really benefit from the increasing glut of renewables. Even better, unlike a sand battery, you can potentially cycle it for several months of summer, by offsetting consumption by just a few hours feels like it could be economically viable. Then again, the competition is general purpose batteries which can be used all year and probably require less maintenance.
- llm_trw 3y agoJust because something seems like should work doesn't mean it will. Air conditioners are simple and cheap to install. An insulated swimming pool in the basement is not.
- dragontamer 3y ago1 cubic meters of water chilled 10C below ambient is 40MegaJoules of energy. Or in other words: 11kW-hrs of cooling, comparable to an entire Tesla Powerwall. We aren't talking about entire swimming pools here. Just a few cubic meters of water. Shift the temperature delta as you see fit but... It's actually very space efficient.
- pi-e-sigma 3y agoTypical residential air conditioning is using 4kW of power. So your 40MJ of energy would be used up in 40MJ/4kW=10000 seconds, or just 3 hours. And its only theoretical, because it assumes 100% efficiency in storage and conversion
- llm_trw 3y agoIt's odd how often battery enthusiasts don't understand the difference between energy and power.
- nimos 3y agoAir conditioners have a COP of about 3 though. So really its more like 3.5kwh of storage. If you want to go lower temperature to store more then your COP drops.
- dragontamer 3y agoThe temperature delta is the hard part for me to estimate here. I know that IceBear left the water around 45F, so take that for what you will. Either way, we aren't talking about entire swimming pools here. Just a small, single digit number of cubic meters of water.
- komali2 3y ago> Air conditioners are simple and cheap to install Today. In my chats with the sort of home improvement types that seem to be in this thread, we're less concerned with today and more concerned with the cost of things in the future, as societies include "climate taxes" (in the form of actual taxes, subsidies, or whatever else) in the cost of things.
- llm_trw 3y agoAnd tomorrow because when you want to cool your house the sun is most likely out.
- dragontamer 3y agoIt definitely seems economically viable to me I'm hoping someone recreates it. It's just a few fans, a tub of water, a pump, and a slightly modified heat pump/air conditioner unit that can safely run down to 50F or so. It's already viable for stadiums and other public events.
- bumby 3y agoThis has been around for a long time. The Detroit VA hospital used it, I believe with tanks under the parking structure. I also believe there were problems related to the maintenance of the tanks. But the important aspect is that this is a cost saving technique, not an energy saving one. You’ll spend more energy because of the thermal losses of the tanks, but hopefully it is more than offset by the cheaper electricity rate.
- taneq 3y agoIf you’re using renewable energy that would otherwise go to waste for lack of storage, then that’s definitely saving (useful) energy.
- dragontamer 3y agoEnergy is (sometimes) free, or even negative priced (!!!!). As it turns out: it's economically infeasible to turn off solar panels, wind, nuclear and sometimes Hydro (depending on water rights, it may be illegal to store water/energy at a water dam). In all of these cases, the energy is 0 cost or even negative cost.
- Danieru 3y agoYou're confused, negative prices are not driven by techincal limitations. Solar, and especially hydro, and even nuclear can shut down just fine. Solar and Wind instead drive prices negative because they have subsidized contracts. Each country is slightly different in implementation, between Feed-in-Tarif vs Feed-in-Premium. In either method there will exist prices which are negative to the market but positive to the producer. Thus if you cannot plan long term to rely on negative prices. Those FIT schemes around the world are transforming into FIP, and the FIP premiums are getting lower and lower. Negative pricing in electricity markets will go away in a decade or two. This isn't magic or even special, solar is succeeding which means the subsidies are getting weakened. Curtailing solar production is not a big deal. How many existing plants have grid operator directed shutoffs depends on your market. In Japan as of 2024 all new non-rooftop solar has it. Prior to 2020ish only Kyushu and Kansai regions required it. Now Tepco, Hokkaido, and Touhoku require it for new contracts. There are still a couple old contracted plants getting developed this year, but those are rarities. And that's only Japan, which itself does not have a super strong duck curve yet: http://jepx.org/ http://jepx.org/ Regions like California have had extreme duck curves for ages. While duck curves are a big worry for internet commentors, they've been points of discussion for grid operators are a lot longer. Hence the move to Feed in Premiums which will slowly make the duck curve a solar operator's problem and not a tragedy of the commons situation.
- abkfenris 3y agoMy local power company worked with a bunch of businesses in my town to install these rather than upgrade the dead end line for a few peak periods.
- ZeroGravitas 3y agoIceBear was competing directly with ever cheaper PV. It's a tech for time shifting cheap overnight energy to the expensive daytime. Installing PV gives you cheap power directly and correlates with air-con demand.
- dragontamer 3y agoNope. You still need aircon at 7pm after the sun begins to set and while solar is losing power. Cooler temperatures aren't until 10pm or so, hours after sunset.
- logtempo 3y agoit's how "rocket stove" works: https://en.wikipedia.org/wiki/Rocket_stove https://en.wikipedia.org/wiki/Rocket_stove Since you burn the wood really fast, you need to delay that heat release. That's where sand comes in as a cheap and good enough material. There are also systems that heat water and store it in a tank, which also make sense if you want hot water in your house too.
- zdragnar 3y agoSand is actually pretty bad. Gravel is a little better, clay is best. Sand is really only useful here because that much clay is usually significantly more expensive and would take forever to dry out. Source: researched the shit out of and have built a rocket stove.