by Steve Hodgson
It is not easy to define distributed (or decentralized) generation (DG), let alone to advocate for policy and regulations to support its wider adoption. The definition generally used in COSPP is electricity generated on-site and largely used at or close to the same location, with or without the use of any heat also generated. This does not have to involve just one building or industrial site ” district energy systems serve a whole district with locally generated heat, and sometimes power. Neither does it matter if a proportion of the power generated is exported to the grid. There are arguments to also include as DG relatively small-scale power generation plants connected to the local electricity distribution network, as opposed to the high-voltage transmission system ” thus avoiding the losses associated with long-distance transmission.
You get the picture: DG tends to be small in scale, is used locally, is often based on combined heat and power or small-scale renewable technologies, and avoids long-distance transmission losses. It can involve gas engines or turbines, PV panels, municipal waste-to-energy, or fuel cells; can be operated by the energy consumer itself, an energy services company or the local utility; and usually delivers efficiency, cost, security and environmental benefits. DG is a broad ‘family’ of technologies and business arrangements, with cogeneration/CHP a central component.
These definition difficulties, and the facts that DG lives neither fully on the supply nor the demand sides of the energy scene ” and often involves heat ” has made the formulation of policies to support the technology family rather challenging. Yet a sustainable energy discussion forum in the UK, Carbon Connect, has done just that, including 23 recommendations in its report: Distributed Generation: From Cinderella to Centre Stage. Aimed at the UK Department of Energy and Climate Change and regulator Ofgem, recommendations are for stable policy measures to encourage investment in DG; more helpful connection policies from distribution network operators; and better regulations on energy storage used with intermittent DG technologies.
Carbon Connect sees DG as a key part of the UK’s efforts to substantially decarbonize the electricity system and meet legally binding carbon reduction targets.
Keep in mind the advantages of DG that flow from its local use and efficiency into reduced carbon emissions, while considering the worst of the centralized alternatives currently being promoted.
Greenpeace has published a report, Point of no return, based on analysis by the Netherlands-based energy consultant Ecofys on the 14 biggest and potentially most environmentally damaging fossil fuel mega-projects at various stages of development around the world.
Australia plans to massively increase coal production, much of this for export; China hopes to achieve an even larger increase in coal production from its north-western provinces; the US and Indonesia both plan to increase coal production and exports; Canada to ramp up oil tar sands production; Brazil to increase offshore oil production; Venezuela to dig out more oil sands, etc., etc. The coal projects, at least, are being driven by the construction of large-scale and centralized coal-fired power plants around the world, particularly in China, India, Russia, Vietnam, Turkey and South Africa.
The point made by Greenpeace is that most of the governments that permit and support these projects also have at least ambitions, if not targets, to control carbon emissions. Many also encourage the development of renewables and DG ” but these fossil fuel mega-projects are of a scale that, in terms of future carbon emissions, would swamp gains made by the more benign alternatives.
Large-scale renewables may be expensive, and DG projects a challenge to legislate for and successfully regulate, but this is where international efforts to modernize and reduce the carbon intensity of electricity systems should be focused. Thus, is there truly a place for a new wave of fossil mega-projects?
Contributing editor, COSPP