- Unreliable: with a poor capacity factor (how long it works at full power)!
- Uneconomic: wind arrives all at once, and then drops off, crashing the price of electricity all at once but then disappearing when we need it!
- If we count the energy cost of storing wind energy, is it even an energy source?
- Denmark and Germany do not have that high renewables penetration
- Wind kills eagles
- Migratory bats may go extinct
1. Unreliable: with a poor capacity factor (how long it works at full power)!
Wind is intermittent and unreliable with a low capacity factor, just like solar PV. Most people think that if we build enough wind turbines across a large continent like Europe, wind’s rise and fall will smooth out. Individual wind farms might die down, but the ‘wind will always blow somewhere.’ This is not always the case! This next graph shows different colours for different countries across Europe from September to March, and you can see the net effect is sudden surges of electricity and then massive, continent-wide drops.
2. Uneconomic: wind arrives all at once, and then drops off, crashing the price of electricity all at once but then disappearing when we need it!
Some wind advocates celebrate the crash in the electricity price as a good thing when all the wind gushes in at once for a time. But this creates a tricky economic situation where you’re trying to sell the spot-market price for electricity ALL AT ONCE! So at lower penetrations of wind, it does OK. But the higher the fraction of your grid that’s made up of wind, the more competition between wind farms drives down the price when it blows. As The Economist reports:-
Electricity markets, especially those that were deregulated in the late 20th century, typically work on a “merit order”: at any given time they meet demand by taking electricity first from the cheapest supplier, then the next-cheapest, until they have all they need; the price paid to all concerned is set by the most expensive source in use at the time. Because wind and solar do not need to buy any fuel, their marginal costs are low. They thus push more expensive producers off the grid, lowering wholesale prices.
If renewables worked constantly that would not, at first blush, look like a problem for anyone except people generating expensive electricity. But renewables are intermittent, which means that in systems where the infrastructure was designed before intermittency became an issue—almost all of them, in practice—fossil-fuel, hydroelectric and nuclear plants are needed more or less as much as ever at times when the sun doesn’t shine and the winds don’t blow. And if such plants are shut out of the market by low-cost renewables, they will not be available when needed.
In the long run, and with massive further investments, electricity grids redesigned for systems with a lot of renewable energy could go a long way to solving this problem. Grids with lots of storage capacity built in; grids big enough to reach out to faraway renewables when the nearby ones are in the doldrums; grids smart enough to help customers adapt demand to supply: all have their champions and their role to play.
But long-run solutions do not solve short-term constraints. So for now countries with lots of renewables need to keep older fossil-fuel capacity available as a standby and to cover peaks in demand. This often means additional subsidies, known as capacity payments, for plants that would otherwise be uneconomic. Such measures keep the lights on. But they also mean that fossil-fuel production capacity clings on—often in particularly dirty forms, such as German power stations powered by brown coal, or backup diesel generators in Britain.
3. If we count the energy cost of storing wind energy, is it even an energy source?
Remember EROEI, Energy Returned Over Energy Invested? It asks not what the economic value is of a wind farm, but how much energy that wind farm returns on the energy invested in building the thing. We need to remember that there are serious questions about whether wind and solar are even high enough energy sources when you count the energy cost of all the storage to get us through the night and winter! Sure, wind has a respectable EROEI of about 23 in itself, but when we include the energy costs of building storage for unreliable wind, the EROEI crashes. See storage page here.
4. Denmark and Germany do not have that high renewables penetration
Watch him lie to the audience about a 47% Denmark grid, as if Denmark had its own independent grid disconnected from the Nord Pool Spot grid, and not also trading with the Synchronous Grid of Continental Europe that serves 400 million customers!
Wind’s story is oversold, like very high fractions of penetration into the Danish grid when national borders are often irrelevant to the much larger international electricity grids. The Danish grid is part of the Nord Pool Spot grid. But their true grid penetration is often disguised behind the fact that the national fraction is so much higher than the actual fraction of the Nordic super-grid.
The reality is that while wind may provide 32 percent of Denmark’s electricity and solar generates 8 percent of Italy’s, for example, these countries and states are really part of much larger power grids. Renewable energy advocates sometimes obfuscate this fact, implying that VRE has reached much higher shares of the power system than they truly have. The Breakthrough.
In other words there is no such thing as a “Danish grid”, they’re part of the Nordic super-grid. There’s no such thing as an “Italian grid”, they’re part of the much larger European super-grid.
As the World Nuclear Association reports:-
Denmark’s electricity mix – a deeper dive
Robust connection between Norway’s hydro turbines and West Denmark’s wind turbines holds the key to successful exploitation of wind for Denmark, and the German and Swedish connections are nearly as importantc. The power imported from Sweden (5.2 TWh in 2011, 2.7 TWh in 2010, 3.8 TWh in 2009, 6.6 TWh in 2008, 5.0 TWh in 2007, 1.7 TWh in 2006, 7.6 TWh in 2005) is almost half nuclear and half hydro. The power imported from Germany (2.9 TWh in 2011, 6.4 TWh in 2010, 3.6 TWh in 2009, 1.4 TWh in 2008, 1.5 TWh in 2007, 4.0 TWh in 2006, 0.6 TWh in 2005) is largely generated by brown coal and nuclear power. (Germany itself imports 9 to 20 TWh/yr from France, which is 75% nuclear.) Norway is almost all hydro.
Hence nuclear power provides an essential part of Denmark’s electricity. In 2011, with imports of 2.9 TWh from Germany and 5.2 TWh from Sweden, it would seem that about 3.5TWh used was nuclear – nearly 11% of total final consumption, and one third of the domestic consumption from wind. This fluctuates year to year, mainly due to NordPool prices, and Energinet.dk analysis showed 1% nuclear in 2010, 7% in 2011 and 14% in 2012.
At the end of 2014, total installed capacity in Denmark was 13.66 GWe, of which 8.15 GWe was thermal generation (mainly fossil fuel-fired) and 4.9 GWe wind turbines. At the end of 2015 wind capacity was 5.07 GWe, 3.8 GWe onshore and 1.27 GWe offshore, the majority in West Denmark (mostly onshore). Wind capacity rose to 4.16 GWe at the end of 2012. West Denmark (the main peninsula part) is the most intensely wind-turbined part of the planet. When it is producing, this power must be taken by the grid. In 2015, the capacity factor for Denmark’s wind capacity was 30.5% due to favourable conditions.
The wind turbines depend heavily for their effective utilization on 29 GWe of hydro capacity in Norway, over 1.7 GWe of which can be dispatched promptly when wind power is unavailable in West Denmark. The Skagerrak HVDC link is owned and operated by Statnett in Norway, and Energinet.dk in Denmark. Hence, there is a natural and felicitous interdependence between West Denmark’s wind and Norway’s hydro. With good winds, power can be exported back to Norway and there conserve hydro potentiale. This explains why the net import-export balance of electricity with Norway is very variablef.
Although about one third of electricity is produced by wind, the country’s use of this electricity is much lower. A 2009 report by Danish policy think tank CEPOS estimates that Denmark consumes around half of its wind-generated electricity on averageg,1. Wind power is heavily subsidized by Denmark but, because this power is exported at the spot price, the subsidies are effectively exported. Moreover, the countries that the wind-generated power is exported to – mainly Norway and Sweden – are largely carbon neutral with regards to power generation, so Denmark’s exported wind power does not save carbon dioxide emissions, instead displacing carbon neutral generation. On the other hand, wind power consumed within Denmark lowers fossil generation in the country.
Danish fossil fuel generation is also lowered during ‘wet’ years in Scandinavia, since the greater hydropower capacity in the north (particularly Norway) becomes more economic than Denmark’s thermal generation. In ‘dry’ years, when Norway and Sweden need to import more electricity, thermal generation in Denmark is higher. For example, total Danish electricity generation was 42.9 billion kWh in 2006 – a dry year – and dropped in subsequent wetter years. This accounts for thermal generation in Denmark being higher in 2006 (33.6 billion kWh) than subsequently, and net exports being higher in 2006 than in following years.
5. Wind kills eagles
The Royal Society 2017 (Point 3e) found that eagles and large birds of prey were by far the most threatened by wind turbines. Of course normal home windows kill millions of little birds each year, but these species are not endangered. The sad irony is that in trying to save the environment, choosing the wrong technologies may threaten our rarer birds of prey. Wind farms kill eagles!
For birds, 936 species had collision rates of more than 0.046 collisions/turbine/yr (90% quartile), of which 174 species were Accipitriformes (figure 2), 57% of species in that order. Accipitriformes had the highest predicted collision rates of any taxonomic order
As “The Conversation” January 2021 said of South Africa
One of these impacts is that wind turbines can kill birds when they collide with the moving blades. This problem is known worldwide, and some types of bird are more vulnerable to this threat than others. Birds of prey, such as eagles, buzzards and vultures, use the same wind resources that turbines need to operate. These large soaring birds use the wind to help power their own flight, using updraughts and thermals to gain height. This can make them particularly vulnerable to collisions with wind turbine blades, which can travel at speeds of up to 290km/hour and either eagles don’t see them or don’t perceive them as a threat until it is too late.
In South Africa, recent research found that 36% of birds killed by wind turbines were birds of prey. These birds have long lifespans and produce relatively few young each year, which means that even a small increase in deaths can cause their populations to decline. This wind-wildlife conflict has been termed a green-green dilemma: more clean energy and healthy bird populations are both desirable environmental goals, yet with detrimental counter effects.
6. Migratory bats may even go extinct!
Large numbers of migratory bats are killed every year at wind energy facilities. However, population-level impacts are unknown as we lack basic demographic information about these species. We investigated whether fatalities at wind turbines could impact population viability of migratory bats, focusing on the hoary bat (Lasiurus cinereus), the species most frequently killed by turbines in North America. Using expert elicitation and population projection models, we show that mortality from wind turbines may drastically reduce population size and increase the risk of extinction. For example, the hoary bat population could decline by as much as 90% in the next 50 years if the initial population size is near 2.5 million bats and annual population growth rate is similar to rates estimated for other bat species (λ = 1.01). Our results suggest that wind energy development may pose a substantial threat to migratory bats in North America. If viable populations are to be sustained, conservation measures to reduce mortality from turbine collisions likely need to be initiated soon. Our findings inform policy decisions regarding preventing or mitigating impacts of energy infrastructure development on wildlife.