71–80 of 258 posts
They have been remote-controlling water heaters in New Zealand and Australia since the 50s. Just a simple relay installed in each house that responses to extra frequencies on the power lines in the 160-1600hz range. It's called ripple control, for obvious reasons. Each home gets assigned to one of several channels in each area so they can have more fine grained control of the load.
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I had a friend who spent months measuring the power output of all his appliances and lights trying to figure out where half his electricity bill was going. He finally realized it was the hot water recirculator.
We have an under-sink unit that has hot water ready 24/7. After hooking it up, I noticed it increased our monthly bill by about $15. I bought a used Wemo plug for $10 and set it to only be on for 3 hours in the morning and 3 hours at night. Now we have hot water at any of the times when we actually would want it, and we aren't wasting money/energy to keep hot water on tap 24/7.
Incorrect. Or rather not necessarily correct. Pumped hydro does not necessarily require damning a river.
> Making matters worse, about a quarter of the energy is cannibalized to do all that pumping.
Pumped hydro is largely considered one of the most efficient forms of energy storage, beating most other methods by a fair amount.
> This approach can be deployed far faster than dam construction, and free of protest (except perhaps from dam builders).
We can't do both?
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Heat pump water heaters mentioned in the article are better for efficiency. They typically use half the energy of a normal water heater. And they cool the air around them, so if you live in a hot area they save more.
My parents got a heat pump water heater (electric) a few months ago and it's great. Definitely the priciest option, but it sips electricity and also cools the area around it (basically operating as an "inside out refridgerator"). In this same remodel I also convinced them to get heat pump / AC combo unit to replace the old gas furnace. Again amazingly cheap (even compared to gas), but also higher upfront cost. This i…
The worst case is efficiency approaches resistance heating at 1.0, maybe with backup resistance heat strips. But a well designed system to match worst case load should rarely see this.
For some reason they've really only been widely available in the US in the past few years.
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The majority of your savings are from switching to gas from electric. Gas is significantly cheaper per BTU. Gas tank heaters are still pretty efficient. Especially if insulated.
It's easy to understand. First, a gas-fired power plant converts about 40% of thermal energy to electricity, discarding 60% to further heat the planet. Then a few more percent are lost in transmission lines and voltage-lowering transformers. Only then that electricity is used to heat water or air in one's house. If you just directly burn that same gas in the house to produce heat, it's nearly 3x as efficient.
Earlier quoted context omitted.
Heat pump water heaters mentioned in the article are better for efficiency. They typically use half the energy of a normal water heater. And they cool the air around them, so if you live in a hot area they save more.
My parents got a heat pump water heater (electric) a few months ago and it's great. Definitely the priciest option, but it sips electricity and also cools the area around it (basically operating as an "inside out refridgerator"). In this same remodel I also convinced them to get heat pump / AC combo unit to replace the old gas furnace. Again amazingly cheap (even compared to gas), but also higher upfront cost. This i…
Can you also store cold cheaply? For example, to run an A/C early in the morning, and put the cold in an insulated tank of a room-temperature phase change material [0]? [0] https://en.wikipedia.org/wiki/Phase-change_material#Common_P...
Most newly built electric cars have a 50+ kWh battery. Imagine if smart meters could use _that_, regardless of where the car is currently parked and plugged in. 50kWh is in excess of what most households use in electricity on most days.
Can you also store cold cheaply? For example, to run an A/C early in the morning, and put the cold in an insulated tank of a room-temperature phase change material [0]? [0] https://en.wikipedia.org/wiki/Phase-change_material#Common_P...
Indeed! The most abundant phase-change material with enormous specific heat of both the liquid phase and the transition to solid is water. Refrigerate water at night, use it during day heat. I see that many groceries use this technique; homes could, too.