Green Power.

Saving Electricity seems to be a good idea, get an Economy 7 meter and use Electricity while it is cheaper. Well that meter may be a bad idea as usually there is additional standing charge for having the meter and you honestly may end up paying more rather than less. However there is a good reason to shift power usage to off peak and that’s to reduce carbon emissions and perhaps keep the wholesale electricity price low, which may reduce in cheaper electricity long term. 

Electricity use isn’t constant there is a fairly predictable demand curve throughout the day and night. The ESB try to match demand with the cheapest generating sources, it’s also complicated by the need to pay generators for not generating. Simply in order to get plant built there needs to be a return on investment otherwise it doesn’t get built and then we wouldn’t have power when needed at peak times.

Renewable Energy such as wind turbines are great converting the free energy of wind to drive a wind turbine and produce power is so much better than burning imported gas which then increases CO2 emissions. 

However there are a few headaches, wind isn’t constant and while in Ireland up to 65% of Electricity can be produced by Wind safely sometimes the wind isn’t there or when it is the demand isn’t.

The maximum wind produced Electricity in Ireland is around 4000 MWatts and Electricity use in Ireland is typically around 3000 to 6000 MWatts depending on time of day. There is some flexibility in that there are a couple of transmission lines that can import and export between Ireland and the UK  for a total of about 1000 MWatts.  Now if demand is low then 4000 Mwatts can’t be put on the grid and Wind has to be curtailed. However if Wind Generation is low say 500 MWatts then more gas burning generators have to make up the difference.  This is why Wind isn’t free, since it has to be backed up with conventional generation and these conventional generators still get paid running or being available.

With the way that demand fluctuates through the day wholesale price is set hourly so it gets cheapest with low demand and most expensive with high demand. Your Energy supplier sets a retail price based on the actual costs to buy your supply on average. It’s better for them when you use off peak power as they make more per unit off peak than they do on peak.  Smart home metering should eventually vary the unit rate to you depending on the wholesale cost. We probably will change our usage with the increased use of Electric cars which we will probably charge at night when demand is lowest and so is the wholesale cost.

So called green energy retail electricity suppliers are not that green they may be wind producers for the grid as well but your electricity supply is from a whole range of sources Wind, Hydro, Gas, Coal, Landfill Gas and others.

Okay that’s kinda complicated what’s our part as consumers in all this, how can we help? It is simple really use your energy hungry devices to times where the demand on the grid is low and reduce electricity use when demand is at its peak. This will help keep the production costs lower, which may keep your unit costs down but also increase the amount of Green Energy that can be put on the grid.

To make things simple lets say the maximum wind power that can be safely put on the grid is 50% (it’s more but I want simple math)  If grid demand is 6000 MWatts then 3000 MWatts of Wind can be put on the grid safely. If demand is 3000M Watts then only 1500 MWatts of Wind can be put on the grid safely. If nationally we have enough Wind Energy available to supply say 2000 MWatts to the grid then 500 MWatts might be curtailed (going to waste since we can’t use it).

By shifting demand from peak to off peak we need less expensive conventional generation at peak time and waste less green energy if its available. 

Now to be fair the way the energy market works currently we don’t really see a lot of financial incentive to move our demand from peak to off peak, the extra metering costs for using cheaper night rate units can offset the discount in the unit price. Conventional metering just records the power going through and not the time, having 2 meters for the peak rate and night rate switching between meters which has been the way for decades isn’t that much better, a smart meter should be able to record your hourly demand and reflect the cost of producing that power. Maybe…

So there is little financial incentive to change our demand from peak to off peak but there is an environmental cost. Our peak demand causes more carbon to be burnt to supply our energy needs and shifting our usage to off peak times allows for greener technology  and lower carbon emission generators to supply our needs and that will help reduce our impact on the environment.  Currently Ireland manages to use about 30% green energy which means 30% less use of conventional generation. If we change to more of peak usage we can improve on that and that will help mitigate climate change.