Page 48

EETE NOV 2014

POWER SUPLIES Making the most of the coming boom in micro-generation equipment By Paul Donaldson In the field of domestic micro-generation of renewable energy, the fog is clearing. In the early 2000s, European governments realised that they needed to take radical steps to avert catastrophic climate change caused by greenhouse gases, and one of these steps was to encourage local, small-scale generation of electricity. Householders and municipalities were encouraged to install equipment such as solar panels, wind turbines, geo-thermal heat exchangers and small hydroelectric turbines. Unfortunately, the technology at the time fell short of politicians’ expectations, generating disappointing quantities of electricity which have done little to reduce Europe’s carbon footprint, and which have come at a considerable financial cost. The policy of micro-generation in Europe looked like a well-intentioned failure. Except now, technology has come to the rescue of the policy-makers, and is set to provide a valuable part of the solution to the problem of carbon dioxide accumulation in the atmosphere. Thanks to a happy combination of better economies of scale as solar panel production has ramped up, improvements in the manufacturing yield from panel factories, and more efficient solar panels (massively increasing the energy output per panel), the cost-per-kilowatt hour of energy from photo-voltaic (PV) panels has dropped through the floor. Some in the industry are now even claiming that grid parity – the point at which unsubsidised solar energy matches the cost of energy generated conventionally in gas- or coal-fired power stations feeding the grid – is in sight. This means that the picture for micro-generation at the domestic and small-industrial scale has suddenly become clear: for most of Europe, solar is widely viewed as the only energy source worth backing. In the next five years, commercial forces alone will fuel a considerable expansion in the number of solar installations on the roofs of buildings across the continent, even if – as is the case in Germany – governments begin to taper the subsidies supporting new solar installations. This expansion will be good for the environment – but it should also be good for Europe’s electronics OEMs. In fact, any manufacturer with experience in high-power electronics, including the ranks of industrial control-equipment makers, should be considering how they can profit from the growth in demand for solar power. But where will these opportunities arise? Build-out of the ‘smart grid’ The growing numbers of roofs with solar panels mounted on them are at risk of disrupting the power grid. In the early days, householders were handsomely rewarded through feed-in tariffs for supplying back to the grid electricity generated but not immediately used. At very low levels, this causes the grid no problems. But if micro-generation solar schemes represent a material portion of the country’s total electricity generation capacity, the existing grid set-up cannot handle feed-in power easily. The current thinking is that grid-stability effects will become potentially damaging when solar is responsible for as much as 20% of total electricity generation. For comparison, today solar accounts for around 5% of total electricity generation in Germany. Solar power is generated in daylight hours; much power usage is in the evening, after the sun has set. Unadjusted, this can mean the grid has excess power when it does not need it, and a shortage when it needs more. The solution is two-fold: the ‘smart grid’, and mass installation of energy storage equipment. The smart grid, based on the installation in every home of a smart meter, allows the grid to regulate power usage automatically. Variable pricing will incentivise users to time discretionary usage of electrical power to times when demand is low. Smart meters could even provide for automatic remote operation of appliances in response to changes in demand for power. At the same time, widespread installation of local energy storage will enable micro-generation schemes, such as solar panels, to store excess energy rather than feed it back to the grid. It will therefore be possible for many householders to become almost grid-independent. This local energy storage will be created in the form of large battery arrays the size of a domestic refrigerator, typically housed in garages and cellars, and as electric vehicles, which could eventually provide a vast source of electrical storage capacity. There is likely to be political and commercial support for the smart grid and for local energy storage, not least because it will help energy utilities to cope better with spikes in power demand, and thus to reduce their need for little-used and expensive reserve power-generation capacity. Paul Donaldson is Sales Director (EMEA) at Future Energy Solutions (a division of Future Electronics) - www.futureelectronics.com 36 Electronic Engineering Times Europe November 2014 www.electronics-eetimes.com


EETE NOV 2014
To see the actual publication please follow the link above