Antinuclear

This myth is disseminated so stridently because renewable energy and energy efficiency have been growing to such an extent over the past decade that they now threaten the existing fossil fuel based business models. Furthermore, wind power is already much less expensive than nuclear energy, and solar photovoltaic power, PV for short, is on the way.

In the past decade, solar PV systems have gone from the most expensive technology for generating electricity to one of the cheapest, despite the global financial crisis. In several parts of the world, including much of Australia, residential solar PV is, over its lifetime, economically competitive with retail electricity prices. Australia has over a million solar roofs and the number continues to grow. Growth has slowed, however, because electricity utilities are paying less for solar electricity fed into the network by households.

During the recent heat wave in South Australia, when air conditioners were running at full blast for weeks, residential solar PV reduced the peaks in electricity demand by nearly five per cent.

Also in South Australia, wind energy is generating 27 per cent of annual electricity demand. As a result, the wholesale price of electricity has dropped substantially and the state’s two coal-fired power stations are closed for half the year. The principal constraint on further rapid growth of wind farms in our windiest state is the absence of a high-capacity transmission link to feed excess wind energy from the small market in South Australia directly to New South Wales.

In Denmark wind energy is already supplying over 30 per cent of annual electricity and is helping the government meet its goals of 50 per cent renewable electricity by 2020 and 100 per cent renewable electricity and heat by 2035. Globally, the price of wind power is still declining, although not as rapidly as that of solar PV.

Meanwhile, over the past decade concentrated solar thermal power has experienced a renaissance in Spain and the USA. Concentrating sunlight to produce heat that can be stored cheaply in tanks of molten salt enables electricity generation at times when the Sun isn’t visible. One solar thermal power station in Spain, called Gemasolar, can generate power 24 hours a day. Because this technology has not yet been reproduced on a similar scale to solar PV, it is still expensive and the financial crisis has stopped its growth in Spain and slowed it in the USA. However, the oil producing countries of the Middle East are building solar thermal power stations so that they can reserve their dwindling reserves of oil for export at high prices.

At the University of New South Wales, a research group comprising PhD candidate Ben Elliston, Associate Professor Iain MacGill and myself has been running hourly computer simulations of the National Electricity Market with electricity demand each hour balanced with 100 per cent renewable energy. We are using current hourly data on demand and weather for solar and wind energy over the region. All the technologies chosen are commercially available: wind, solar PV, concentrated solar thermal power with thermal storage, existing hydro-electricity and gas turbines fuelled on renewable gases and liquids produced from organic residues.

We’ve scaled them up in our model, and performed the simulations with many different mixes of these renewable energy technologies and with different operating conditions. Even when the total contribution of the most variable sources, wind and solar PV, is as high as two-thirds of annual electricity generation, the renewable energy system can still provide the same high reliability as the existing fossil fuelled generation system.

Yet, strictly speaking, not one of our technologies is a base-load power station, and the amount of storage in the system is tiny compared with annual electricity generation. So how can it be so reliable? As explained in more detail in my book Greenhouse Solutions with Sustainable Energy, the fluctuations in wind and solar PV are balanced by reliable, flexible, peak-load power stations—hydro-electricity and biofuelled gas turbines—together with concentrated solar thermal power with thermal storage.

Conventional base-load power stations are too inflexible to supply daily peaks in demand or to balance the fluctuations in variable renewable energy sources. Conventional base-load power stations perform best when they operate continuously at their maximum design power output, just supplying the base demand. In a system supplied predominantly by renewable energy technologies, inflexible base-load power stations like coal and nuclear simply get in the way.

So, the myth that 100 per cent renewable electricity cannot be achieved without base-load power stations such as coal and nuclear, or vast amounts of energy storage, is busted. Computer simulations by overseas research groups that span up to ten years of real data on electricity demand and weather obtain similar results.

The real challenge of running a system of 100 per cent renewable electricity isnot supplying base-load demand, which is easy; it is meeting the peaks in demand. For this we need flexible peak-load stations.

By the way, flexible gas turbines are similar to jet engines and have a low capital cost. When run continuously, as on a long jet flight, their total fuel cost becomes very large. But in our simulations the biofuelled gas turbines are only needed to fill a few small gaps in supply, especially to help meet the peaks on calm winter evenings following overcast days. They act as reliability insurance—with a low premium. Moreover, the reliability of a 100 percent renewable electricity system can be increased even further by spreading wind and solar power stations geographically into different weather zones.

Additional security of supply will be achieved as our electricity system evolves into a so-called ‘smart’ system, in which demand peaks can be reduced for an hour or two when available supply is low, such as on calm winter evenings. Such demand management is already being practised to a limited degree by offloading aluminium smelters for up to two hours without damaging the smelting process. Once ‘smart’ devices have been installed, residential air conditioners and even refrigerators can be offloaded for short periods on a rotational basis, without adverse consequences. Customers who sign up for being part of such a ‘smart’ system would of course be rewarded by paying a smaller supply charge.

While renewable energy has grown rapidly and become much cheaper in the 21st century, proponents of coal-fired power stations with capture and storage of carbon dioxide emissions have found that their technology of choice is much more difficult to bring to commercial reality than originally claimed, and is therefore going to be much more expensive.

Our research group at the University of New South Wales has compared the projected costs of a 100 per cent renewable electricity system in 2030 with those of various fossil-fuelled systems with carbon capture and storage. To establish the cost of renewable electricity we took the original conservative projections made by the federal government’s Bureau of Resources and Energy Economics. Because carbon capture and storage will not become commercially available on a significant scale for decades, we considered a wide range of future costs of that technology and a wide range of carbon prices, from zero upwards…….

In summary, the principal barriers to 100 per cent renewable electricity in Australia are no longer scientific, technological or even economic. They are the political power of the smokestack industries of the 19th and 20th century—coal, oil, gas and the large electricity utilities—which are fighting to delay being replaced by the sustainable energy industries of the 21st century, energy efficiency and renewable energy.

These vested interests have been lobbying federal and state governments to remove the modest carbon price, to cut the inexpensive Renewable Energy Target, to terminate the profitable Clean Energy Finance Corporation, to cut funding for research and development through the Australian Renewable Energy Agency, to cut feed-in tariffs for renewable energy, to limit public information by abolishing the Climate Commission, and to remove a source of independent expert advice to government by abolishing the Climate Change Authority.

In the words of Greens Senator Christine Milne: ‘We are now in the midst of a fight between the past and the future.’

It all depends on you, the citizens of Australia, demanding a better energy future based on the efficient use of renewable energy. http://www.abc.net.au/radionational/programs/ockhamsrazor/renewable-energy/5287980