CPV I GRID OPTIONS
A basic micro-desalination unit – the size of an average
washing machine, requires 800 Watts of electricity to produce 1,000 litres a day. This is enough for a family’s daily needs. A single CPV unit could power four of five of these machines, providing an energy efficient, affordable power source
For most off-grid power generation around the world the main option remains diesel generation, despite the expense and logistics of running them. Generating electricity using diesel engines is far from ideal. It is expensive, noisy and it leaves a high carbon footprint. In addition, steady power generation demands regular supplies of fuel, with additional economic and environmental costs for transportation over large distances.
Why CPV?
Solar power offers the potential for cheap, reliable, carbon-free power. Moreover, the high efficiency levels of CPV make it highly suitable for widely distributed micro-generation installations. Despite Western reservations about micro-generation, the technology has obvious and immediate benefits for the developing world. For example, a basic micro-desalination unit, the size of an average washing machine, requires 800 Watts of electricity to produce 1,000 litres a day. This is enough for a family’s daily needs. A single CPV unit could power four of five of these machines – providing an energy efficient, affordable power source.
And CPV can achieve this at a far lower price than diesel. Whereas the initial cost of a solar power system is higher than a diesel generator of the same power rating, the fuel from the sun is free. In order to compare the economic case of generating electricity from diesel with CPV, we need to look at the total cost of generating each unit of electricity over the system life, best summarised as the levelised cost of electricity (LCOE).
The LCOE for diesel generated electricity varies greatly from country to country, because there is a wide range in the cost of diesel fuel, but it is typically in the range 50-100¢/kWh. By contrast, the LCOE for CPV in the countries having good levels of direct sunlight is currently 15-30¢/kWh. Furthermore, this is rapidly reducing, as CPV efficiency improvements are realised and economies of scale are achieved. Over the next five years or so, CPV LCOE will come down below 10¢/kWh.
So clearly there is a huge opportunity in off-grid deployments, not just for CPV, but also for renewables in general. However, CPV has several advantages over the other competing technologies. Unlike concentrated solar thermal power (CSP), photovoltaic technologies generate electricity directly from the sunlight. More importantly, CPV does not consume cooling water. CPV systems also produce more watts per area of solar panel and maximise energy production per hectare compared with conventional PV systems. In addition, the energy consumed in manufacture of CPV systems is less than a third that of conventional PV systems. A further major advantage of CPV over
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PV for off-grid installations is that the performance degradation of silicon. PV at high temperatures is far greater than for CPV. This means that a CPV system will produce more electricity than a silicon. PV system of the same rating in hot and sunny
locations.It is also important not to ignore the support and maintenance requirements for any power generation. Systems designed for a long lifecycle and that require minimal and simple maintenance are most suitable, these are both properties of CPV systems.
Off-grid applications for CPV There are a number of potential applications for off-grid applications of CPV systems. As mentioned earlier, water desalination has great potential for CPV, but there are far more potential off-grid applications. For example, CPV installations can provide power during the day for hospitals and schools that are either too remote to have access to grid electricity or suffer from
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