I received an interesting flyer in the mail yesterday. It was titled:
Replace Hazelwood with Clean Energy Now.
The flyer does not make it clear what clean energy we are meant to use. However, I doubt that the supporters of the campaign mean hydro, nuclear or gas-fired plant. I suspect they would be referring to wind generation. So let’s ask a simple question: can we replace Hazelwood with wind energy now?
Hazelwood Power Station in Victoria’s Latrobe Valley has a capacity of 1600 MW. It has long been one of Australia’s dirtiest coal-fired power plants and probably should be replaced if Australia is serious about cutting greenhouse gas emissions.
To replace the name-plate capacity of Hazelwood would require a windfarm or a series of wind farms that would in total be about one-and-one-half times the largest wind farm in the world. This is doable. After all Victoria has a large amount of coastline and we can fill the rolling hills of Gippsland with wind turbines if we choose to. The environmental amenity would be severely damaged but it would reduce carbon emissions.
However, this is simply nameplate capacity. We need to take into account availability. Coal’s load factor (roughly, how much power you can get out relative to name-plate capacity) is around 65 to 85% according to this website (which is pro-wind power). Wind has a load-factor of 25 to 40% according to the same website. This sounds like a generous load factor for wind, but let’s go with it. The implication is easy. To replace Hazelwood we need approximately twice the nameplate capacity of wind generation.
In other words to replace Hazelwood Power Station with wind we would need a windfarm or set of wind farms that in total are three times the size of the largest wind farm in the world. Again this is doable, but I suspect we would lose either a few of our coastal national parks or a big chunk of Australia’s most productive dairy country.
However the problem doesn’t end there. Load factors give an indication of output. But they do not give an indication of flexibility. Wind may give some power a lot of the time but it cannot be geared up down according to the needs of the electricity system. So in summer in Victoria almost all coal generation will be available. The system operator does not allow generators to undertake routine maintenance in periods when the demand for electricity is expected to be high. In contrast the system operator cannot tell the wind to blow harder. So if Hazelwood is replaced by wind generation and demand is high during Melbourne’s winter or summer peaks, but the wind is not blowing, then the lights, the air conditioners, the hot water and so on will stop – at least in the areas the system operator blacks-out.
This may not be a problem, at least to those who do not mind having their lights and heat go off in winter or the air conditioning go off in summer. However I suspect it would be an environmental disaster. Many people’s immediate reaction to a lack of reliability of the power supply will be to get insurance. The simplest insurance for failure of electricity is to have your own generation. So replacing Hazelwood with wind would almost certainly lead to a massive increase in the number of households with back up diesel generation. Of course this generation, in terms of carbon emissions, is a disaster.
Of course it is unlikely to get to that. Any state government that allowed power to regularly fail on either hot summers days or cold winters nights would not be the government for very long. Politically it will not happen. The government will insure the electricity system by building more generation capacity that could be reliably called on at short notice. In other words the wind capacity would be augmented by substantial gas fired generation capacity.
So could we replace Hazelwood with wind? Yes, but it would require wind generation that is 3 times the capacity of the world’s largest wind farm, and it would probably require another 800 MW or so of backup gas-fired generation. And in terms of amenity, it would be an environmental disaster.