Waste not, want not

Energy efficiency measures are a simple and fast-working way to help us slow down global temperature increases, says Andy Clarke

“Energy management isn't a matter of life and death – it's the only way we'll save the planet.“Quite a few years ago, my young daughter (she's now a mother herself – that's how long ago) said those words to me as I was going to give a course to energy champions. Now, we'll have to forgive her youthful inaccuracy, as the planet will technically 'survive', even if surface conditions become comparable to those of Venus. It is life that may be destroyed in the next few years if we don't take drastic action.

“Energy efficiency measures are often not constrained by long timescales and can therefore deliver savings almost immediately“

However, it is very true that the unfashionable profession of energy efficiency management will play an essential part if we are to, for example, keep global warming below 2ºC. Much focus has been on replacing fossil fuel technologies with ones that are less harmful to the global carbon dioxide concentrations, which will be essential in the long term.

The sooner we start to decrease carbon emissions, the less long-term damage will occur; the less habitat change will affect flora and fauna (and thereby extinctions), and the less we will have to take painful steps in the future.

Energy efficiency measures are often not constrained by long timescales and can therefore deliver savings almost immediately. Even if we achieve the draconian reductions required by 2050 by international agreement, all may be to no avail if we allow excess emissions now – much of which will still be in the atmosphere then. Immediacy of change matters and energy efficiency can be the quickest at that.

We should also consider the cost-effectiveness of using energy efficiency as a major weapon against climate change. Measures are often free, or at least very cheap. For example, what does it cost to turn off unused appliances (or, even better, unplug them, so any primary transformers are isolated and their standing losses can be saved)? A more 'industrial' example relates to compressed air. A pinhole leak in a typical eight-bar system absorbs around a kW of power. Fixing that may take an engineer a few minutes with a wrench and possibly a little jointing compound. If we were to instead generate an additional kW, because we were too lazy to apply the simply energy efficiency measure, the additional plant (even at scale) would cost at least £1,000 from 'conventional' technology and probably two or three times that using clean technologies such as wind, solar or biomass. Reducing wastage by making practical energy efficiency measures has to be more efficient and cost effective than spending money on renewable generation and then wasting lots of it.

There is another consideration: we are going to have to do massive amounts of work on our energy infrastructure to reflect the move from large centralised plant to more localised ones. This will affect our electricity grid, our natural gas mains (especially if we turn them over to carry hydrogen, as the H21 project suggests) and any district heating/cooling systems, and we will need to carefully consider sizes. If we enact energy efficiency measures in our building stock first, we will be able to size the modified supply systems to reflect a lower level of usage and consequently make significant savings. As it happens, correct sizing is also likely to mean better control, and even more savings as a result.

New buildings (built to high energy performance certificate ratings, 'Excellent' BREEAM and the latest building regulations) that incorporate advanced energy saving measures will only be small proportion of the building stock in 2050 – the year by which we have agreed to make the bulk of our energy saving measures. We will therefore need to reduce the consumption of existing buildings. Retrofitting items such as solar panels can only do so much – we will need 'conventional' energy efficiency measures.

When the EU published its 20-20-20 plan for reduction of carbon emissions by 2020, it decided that 20% energy savings from improved energy efficiency were possible. It would appear that we need to exert more effort in that less fashionable aspect of reducing carbon emissions if we are to comply with things like the Kyoto and Paris Agreements in a cost-effective manner, and prevent the temperature of the planet rising to a point that irreversible harm is done to the planet. We need strong leadership in that direction.

Andy Clarke, AIEMA is chair of the North Eastern Branch Energy Institute