9 ms·

> but theptip writes below that heating water in residential and commercial settings might be better. When I worked at Ørsted, we did this all the time. We had

> but theptip writes below that heating water in residential and commercial settings might be better. When I worked at Ørsted, we did this all the time. We had a huge electric kettle, which we used to produce district heating water. But there are many more things you can do with surplus energy. You can make methane gas from pure CO2 and hydrogen when you apply electric power as a catalyst. The methane can then be eaten by bacteria to provide protein powder to be used as supplements to feeding livestock. Or, we can yank CO2 out of the atmosphere and store it as ethanol. I think this was discovered last year or so? Ethanol is a really good "battery", and it only discharges as much CO2 as was captured by the surplus energy used to make it, making it a clean fuel that only exhausts CO2 and sterile water.

hvidgaard 8y ago
I was at a tour of Skærbækværket many years ago, and as I remember it, when you produce power, you need to be able to control the voltage somehow. If there is a surplus of power and you cannot turn down production, you need to dump it or the voltage will go up, destroying electrical systems. One of the simplest ways to do this is to heat water, and when you have well established district heating it's almost a no brainer what to do.
- undreren 8y ago
  It's a nobrainer, but the electric kettles are rather expensive and are usually therefore only bought to ensure production capacity in the case that the powerplant's own kettle malfunctions. Besides, district heating produced on power from the grid is taxed as if produced on coal, as the power has no traceability. This makes it really expensive, unless you are directly hooked up to a solar or windfarm. That's the law in Denmark at least. PS: I worked in the administrative building just next door to Skærbækværket! :)
  - hvidgaard 8y ago
    Ahh, it doesn't make much sense to install it away from a powerplant. It captures waste heat and electricity, where as one elsewhere would only be able to capture excess electricity.
  - Shoh3pif 8y ago
    > district heating produced on power from the grid is taxed as if produced on coal, as the power has no traceability. Sounds like there is room for improvement. E.g. an agreement with an energy provider and tracking when it was used on demand as a sink for excess energy instead of base-rate heating.
fuzzbuzz 8y ago
A banal long term way of storing energy is to pump water up to some high ground. Whenever you need it, use a turbine to get the energy back.
- undreren 8y ago
  That requires big water deposits up in the mountains, along with a dam. Norway is having great success with this strategy on their hydro plants.
  - andygates 8y ago
    The UK pretty much exhausted its stock of good, easy, large sites with Dinorwig.
- jasoncartwright 8y ago
  This is exactly how the 6th largest power plant in the UK works (but the turbine is reversed to become the pump) https://www.youtube.com/watch?v=McByJeX2evM https://www.youtube.com/watch?v=McByJeX2evM https://electricityproduction.uk/plant/GBR1000151/ https://electricityproduction.uk/plant/GBR1000151/
  - uxp 8y ago
    There's a number of them all over the world. Surprisingly simple idea and amazingly powerful storage. https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroelectric_power_stations https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroel...
- forkerenok 8y ago
  this reminded me of underwater energy storage pilot: https://arstechnica.com/science/2017/03/german-institute-successfully-tests-underwater-energy-storage-sphere/ https://arstechnica.com/science/2017/03/german-institute-suc...
  - eloff 8y ago
08-15 8y ago
> We had a huge electric kettle, which we used to produce district heating water. ...and you thought you were heating with renewable energy. You were not. Much of the "surplus" power on the grid comes from coal plants (especially in Denmark!) that can't throttle down, so someone burns coal, converts the heat to electricity at an efficiency of 40% or so, and you turn it back into heat.
- undreren 8y ago
  > ...and you thought you were heating with renewable energy. No we didn't. As a mathematical modeller and software developer for their inhouse production optimization software, I was perfectly aware of what was happening. > Much of the "surplus" power on the grid comes from coal plants (especially in Denmark!) Most of the power plants owned by Ørsted are bio-converted and runs primarily on wood chips and pellets. Unless you are talking about surplus energy imported from Germany, what you say simply isn't true. Besides, the huge amounts of surplus energy that often came from germany were caused by their massive open sea wind farms, making the energy pretty green. Ørsed operated almost exclusively combined heat and power plants, meaning that they can produce heat and power concurrently. The utilization of energy was well above 90%, when we ran the plants this way, because we cooled the plant with the district heating water, instead of sea water. The theoretical maximum is ~98%. We also never planned for pure power production, only to turn it into heat again. That would be monumentally stupid. We had many, highly skilled engineers and power traders, and they absolutely knew what they were doing.
  - 08-15 8y ago
    So it seems many coal burners in Denmark have switched top biomass in the past few years. I didn't know that. But someone burning wood to make electricity and someone else wasting the electricity in a resistance heater still doesn't sound like a solution, it sounds like insanity. (Not necessarily pointing fingers at you personally. Negative prices lead to insanity.)
MertsA 8y ago
>You can make methane gas from pure CO2 and hydrogen when you apply electric power as a catalyst. You can make methane gas from pure CO2 and hydrogen period. The reaction is exothermic, it's just the Sabatier method. You could however use electricity to split water into hydrogen and oxygen.

hvidgaard 8y ago

I was at a tour of Skærbækværket many years ago, and as I remember it, when you produce power, you need to be able to control the voltage somehow. If there is a surplus of power and you cannot turn down production, you need to dump it or the voltage will go up, destroying electrical systems. One of the simplest ways to do this is to heat water, and when you have well established district heating it's almost a no brainer what to do.

undreren 8y ago
It's a nobrainer, but the electric kettles are rather expensive and are usually therefore only bought to ensure production capacity in the case that the powerplant's own kettle malfunctions. Besides, district heating produced on power from the grid is taxed as if produced on coal, as the power has no traceability. This makes it really expensive, unless you are directly hooked up to a solar or windfarm. That's the law in Denmark at least. PS: I worked in the administrative building just next door to Skærbækværket! :)
- hvidgaard 8y ago
  Ahh, it doesn't make much sense to install it away from a powerplant. It captures waste heat and electricity, where as one elsewhere would only be able to capture excess electricity.
- Shoh3pif 8y ago
  > district heating produced on power from the grid is taxed as if produced on coal, as the power has no traceability. Sounds like there is room for improvement. E.g. an agreement with an energy provider and tracking when it was used on demand as a sink for excess energy instead of base-rate heating.

fuzzbuzz 8y ago

A banal long term way of storing energy is to pump water up to some high ground. Whenever you need it, use a turbine to get the energy back.

undreren 8y ago
That requires big water deposits up in the mountains, along with a dam. Norway is having great success with this strategy on their hydro plants.
- andygates 8y ago
  The UK pretty much exhausted its stock of good, easy, large sites with Dinorwig.
jasoncartwright 8y ago
This is exactly how the 6th largest power plant in the UK works (but the turbine is reversed to become the pump) https://www.youtube.com/watch?v=McByJeX2evM https://www.youtube.com/watch?v=McByJeX2evM https://electricityproduction.uk/plant/GBR1000151/ https://electricityproduction.uk/plant/GBR1000151/
- uxp 8y ago
  There's a number of them all over the world. Surprisingly simple idea and amazingly powerful storage. https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroelectric_power_stations https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroel...
forkerenok 8y ago
this reminded me of underwater energy storage pilot: https://arstechnica.com/science/2017/03/german-institute-successfully-tests-underwater-energy-storage-sphere/ https://arstechnica.com/science/2017/03/german-institute-suc...
- eloff 8y ago

08-15 8y ago

> We had a huge electric kettle, which we used to produce district heating water. ...and you thought you were heating with renewable energy. You were not. Much of the "surplus" power on the grid comes from coal plants (especially in Denmark!) that can't throttle down, so someone burns coal, converts the heat to electricity at an efficiency of 40% or so, and you turn it back into heat.

undreren 8y ago
> ...and you thought you were heating with renewable energy. No we didn't. As a mathematical modeller and software developer for their inhouse production optimization software, I was perfectly aware of what was happening. > Much of the "surplus" power on the grid comes from coal plants (especially in Denmark!) Most of the power plants owned by Ørsted are bio-converted and runs primarily on wood chips and pellets. Unless you are talking about surplus energy imported from Germany, what you say simply isn't true. Besides, the huge amounts of surplus energy that often came from germany were caused by their massive open sea wind farms, making the energy pretty green. Ørsed operated almost exclusively combined heat and power plants, meaning that they can produce heat and power concurrently. The utilization of energy was well above 90%, when we ran the plants this way, because we cooled the plant with the district heating water, instead of sea water. The theoretical maximum is ~98%. We also never planned for pure power production, only to turn it into heat again. That would be monumentally stupid. We had many, highly skilled engineers and power traders, and they absolutely knew what they were doing.
- 08-15 8y ago
  So it seems many coal burners in Denmark have switched top biomass in the past few years. I didn't know that. But someone burning wood to make electricity and someone else wasting the electricity in a resistance heater still doesn't sound like a solution, it sounds like insanity. (Not necessarily pointing fingers at you personally. Negative prices lead to insanity.)

MertsA 8y ago

>You can make methane gas from pure CO2 and hydrogen when you apply electric power as a catalyst. You can make methane gas from pure CO2 and hydrogen period. The reaction is exothermic, it's just the Sabatier method. You could however use electricity to split water into hydrogen and oxygen.