Solar power is expensive. That has always been the accusation. By the time you have manufactured large, inefficient sheets of solar cells and mounted them on roofs or in dedicated installations, the cost per Kilowatt Hour (kWh) is much higher than for coal or nuclear counterparts.
Expect that it isn’t. And even if it is, it won’t be.
In the last few months there have been two interesting reports on solar power and some fascinating shifts in the underlying technology of the solar cell.
The first report in May last year came from an organisation called GlobalData. It highlighted that solar power is getting more economical all the time, as the efficiency of the technology and the scale of its deployment increases. Using a measure called the Levelised Cost of Electricity to compare sources on an even basis, taking into account the cost of generation, solar power will hit parity with market prices for electricity in 2017.
Solar power will be cheaper than nuclear or coal in just four years time. That’s not long when you are considering the construction of new power plants.
The second report in September last year was slightly more partisan, as it was conducted by a political lobbying organisation in Germany with environmental goals. Its findings are fascinating though.
If you try to account for the environmental and health costs of energy generation, then solar power is already on a par with other forms of generation, and wind power is even cheaper. These costs are not insignificant: take for example, the cost of cleaning up old nuclear reactors, or the cost to the National Health Service from coal pollution.
With societal costs taken into account, wind power costs around 6p per kWh, solar between 10p and 18p. By contrast the societal costs alone of coal are 9p per kWh. New nuclear power plants are way more expensive at between 31p and 54p per kWh.
Solar power suffers because it does have an environmental cost. The materials from which solar cells are manufactured can be pretty unpleasant, as can the processes used to manipulate them. Certainly a lot of electricity is consumed in the making. And because the cells are relatively inefficient — around 14% of the light energy hitting the cell gets turned into electricity — it’s hard for them to overcome these costs.
This could be changing. The US Department of Energy announced last week that it is investing an extra $12m in its programme of grants for research into advancing solar generation. This is on top of $35m already invested — peanuts in energy terms but at least the intentions are good. This money is going to places like Texas University’s Cockrell School of Engineering where they are already producing printable solar cells with 6% efficiency. These are made by printing a material onto a glass substrate and are up to 10 times cheaper to produce than their chunky current equivalents. Their efficiency is climbing all the time — Swiss researchers at the Empa Research Institute have demonstrated flexible solar cells with efficiency over 20%, though not so easy to manufacture.
There are operational issues with renewables to overcome: such as delivering energy when the wind doesn’t blow and the sun doesn’t shine. But these are far from insurmountable — certainly when the sums involved are considered. Battery technology is advancing apace and trailer-sized Lithium Ion units already being used to smooth power delivery to cities.
Overcoming these challenges is simply a matter of time and directing resources to the right ends. Increase in electricity usage has slowed dramatically in some western countries (including the US), thanks to greener living and technologies such as LED lighting that are an order of magnitude more efficient than their predecessors. We should be able to generate our remaining needs cleanly and cheaply from the sun.