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Still don't get how that works. A 114MW wind farm almost never produces 114MW. In fact, it's output is fairly unpredictable, and can swing from 10MW to 90MW and

Still don't get how that works. A 114MW wind farm almost never produces 114MW. In fact, it's output is fairly unpredictable, and can swing from 10MW to 90MW and back to 20MW over the course of 30-40 minutes. When a company that requires high levels of constant power "buys" that power, what are they buying, exactly? Because they're still just as reliant on nuclear/coal/natural gas as they were before they bought that power. Are they just signing up to pay a higher rate for those 114MW of power they get from the grid?

twohlix_ 9y ago
They are guaranteeing for that producer their power is purchased at x$/whatever for 20 years. Massively lowers the risk profile for the wind farm, and lets them focus on potentially expanding. Google is basically acting as a subsidizer of renewable energy here. So while yes they rely on the grid, they're a market force for increasing the percent of the power produced on the grid to be renewable. Every MW produced by the renewable is a MW not needed to be produced by natural gas/coal
- CydeWeys 9y ago
  > Every MW produced by the renewable is a MW not needed to be produced by natural gas/coal This should be expressed in units of energy, not power, i.e. MWh.
- strictnein 9y ago
  I guess that makes more sense. It's more an act of corporate goodwill on their part, helping to build a certain level of renewable energy.
  - tedsanders 9y ago
    Partly. But it's also an act of risk hedging. By locking in prices for 20 years, the buyer is insulated from rising prices and the generator is insulated from falling prices.
ant6n 9y ago
Presumably they pay more money for the renewable energy, overall increasing the demand for renewables and decreasing demand for coal.
WJW 9y ago
They are not "just as reliant as before", they are only reliant on gas/coal/whatever when the wind is having a dip. It is clearer when you look at the energy consumed in joules: A 114 MW datacenter consumes 114* 10^6 * 3600* 24 Joules per day. The renewable power generator that Google has a contract with commits itself to putting that much Joules into the grid every day. When the wind is out, nonrenewables fill up the slack, and when there are high winds, some of the customers that would have otherwise been supplied from coal plants get wind energy instead. On average though, 114 MW is pulled out of the grid by the datacenter and 114 MW is put in by the renewable energy company. The rest of the grid, bith producers _and consumers_, act as a battery for when the output of the renewables is either higher or lower than the contracted amount for the datacaenter.
- strictnein 9y ago
  > "On average though, 114 MW is pulled out of the grid by the datacenter and 114 MW is put in by the renewable energy company." That's simply not the case. Wind farms fluctuate greatly and produce on average no where near their max output. > "they are only reliant on gas/coal/whatever when the wind is having a dip" Which is all the time. I've worked on this problem, there isn't some constant output from wind farms.
  - crazy2be 9y ago
    This is at best a tangential point. If the wind farm is 114MW with a 10% capacity factor, his point is still correct. Yes, they still rely on coal and natural gas to smooth the load, but his point was that by subsidizing the wind power, they still reduce emissions the same amount as if they didn't. Obviously, this strategy only works when renewable penetration is fairly low, once you start having oversupplies then you no longer have 100% efficiency with this strategy.
  - minwcnt5 9y ago
    Would it make you happy if they had written "On average though, x MW is pulled out of the grid by the datacenter and x MW is put in by the renewable energy company, where x is some value < 114 MW"? Sheesh. The point being made is pretty clear.

twohlix_ 9y ago

They are guaranteeing for that producer their power is purchased at x$/whatever for 20 years. Massively lowers the risk profile for the wind farm, and lets them focus on potentially expanding. Google is basically acting as a subsidizer of renewable energy here. So while yes they rely on the grid, they're a market force for increasing the percent of the power produced on the grid to be renewable. Every MW produced by the renewable is a MW not needed to be produced by natural gas/coal

CydeWeys 9y ago
> Every MW produced by the renewable is a MW not needed to be produced by natural gas/coal This should be expressed in units of energy, not power, i.e. MWh.
strictnein 9y ago
I guess that makes more sense. It's more an act of corporate goodwill on their part, helping to build a certain level of renewable energy.
- tedsanders 9y ago
  Partly. But it's also an act of risk hedging. By locking in prices for 20 years, the buyer is insulated from rising prices and the generator is insulated from falling prices.

ant6n 9y ago

Presumably they pay more money for the renewable energy, overall increasing the demand for renewables and decreasing demand for coal.

WJW 9y ago

They are not "just as reliant as before", they are only reliant on gas/coal/whatever when the wind is having a dip. It is clearer when you look at the energy consumed in joules: A 114 MW datacenter consumes 114* 10^6 * 3600* 24 Joules per day. The renewable power generator that Google has a contract with commits itself to putting that much Joules into the grid every day. When the wind is out, nonrenewables fill up the slack, and when there are high winds, some of the customers that would have otherwise been supplied from coal plants get wind energy instead. On average though, 114 MW is pulled out of the grid by the datacenter and 114 MW is put in by the renewable energy company. The rest of the grid, bith producers _and consumers_, act as a battery for when the output of the renewables is either higher or lower than the contracted amount for the datacaenter.

strictnein 9y ago
> "On average though, 114 MW is pulled out of the grid by the datacenter and 114 MW is put in by the renewable energy company." That's simply not the case. Wind farms fluctuate greatly and produce on average no where near their max output. > "they are only reliant on gas/coal/whatever when the wind is having a dip" Which is all the time. I've worked on this problem, there isn't some constant output from wind farms.
- crazy2be 9y ago
  This is at best a tangential point. If the wind farm is 114MW with a 10% capacity factor, his point is still correct. Yes, they still rely on coal and natural gas to smooth the load, but his point was that by subsidizing the wind power, they still reduce emissions the same amount as if they didn't. Obviously, this strategy only works when renewable penetration is fairly low, once you start having oversupplies then you no longer have 100% efficiency with this strategy.
- minwcnt5 9y ago
  Would it make you happy if they had written "On average though, x MW is pulled out of the grid by the datacenter and x MW is put in by the renewable energy company, where x is some value < 114 MW"? Sheesh. The point being made is pretty clear.