Mary Mulvihill » electricity

Earth hour 2009, the LHC and greening your electricity

marymulv — Tue, 10 Mar 2009 22:18:53 +0000

We can’t all install a wind turbine at the bottom of the garden, yet simply changing when we use electricity can make our power consumption greener.

Some years ago, making a science programme for RTE radio, I was let into the inner sanctum where skilled engineers control the Ireland’s electrcity supply to meet the constant rise and fall in demand across the national grid.

There, in a darkened room (the better to see all the computer displays), the Eirgrid engineers work not unlike air traffic controllers. They have their fingers on the pulse of the nation, and their hands (literally) on the levers of power.

Electricity consumption in Ireland rose steadily over recent years. All those new homes, all those new appliances, all those switched-on lives. So much so that demand was almost outstripping supply, and new power plants were planned. (It will be interesting to see if peak demand falls over coming months as the recession bites.)

Demand is highest in winter, as you might expect, but not on Christmas day as I had thought. (Surely, with all those turkeys in all those ovens, all those lights on all those trees? But no: lots of households get together, and more importantly, most industry has shut down.)

No, the worst time — when supply from power plants has trouble meeting demand — is 5-7pm on cold winter week nights. That’s the electric rush hour, when the heating is on and everyone is cooking dinner in homes across the country, and all the power stations have to be brought on stream, including older and more polluting and inefficient ones.

In other words, it’s the dirtiest time for electricity generation.

(And the most expensive: commercial customers may be charged more for rush hour electricity. This is why CERN’s LHC experiment on the Swiss-French border will shut down for three months every winter: particle accelerators are heavy power users, and winter electricity is just too expensive, even for the world’s biggest experiment.)

Power production is cleanest and greenest, on the other hand, when demand is lowest – usually late at night.

So, if you want greener electricity, and can’t install a wind turbine, here’s a simple tip: spread your electricity consumption more evenly across the day, and try to reduce consumption during the peak hours of 5-7pm.

Leave the dishwasher and clothes wash till later, maybe use a microwave instead of a conventional oven, listen to the radio news instead of the TV.

By reducing peak demand, you’re helping to reduce the number of new power plants needed!

You can monitor Irish electricity demand and supply in real time on the Eirgrid website. Here’s a recent snapshot of the system (left), taken on the evening of March 10th 2009.

And at 8.30pm on Saturday March 28th, why not turn off all your lights? And join millions of others around the world in marking Earth Hour.

If enough city dwellers do it, you might even get to see the stars again. And if you can survive an hour in the dark, then you don’t have to turn all the lights back on at 9.30pm! Fewer lights burning? Think of it as ambience.

And remember: night-time electricity is cleaner and greener. So, spread the workload, and spread the word.

Who do you buy your electricity from?

marymulv — Fri, 24 Oct 2008 14:47:00 +0000

Veteran environment journalist Fred Pearce has started a new Green Wash column at The Guardian.

His opening salvo examines the question of green electricity supply, and green energy tariffs — the scheme that lets British energy customers pay a premium for green energy. But, as Pearce reveals, there is no guarantee that the extra money is used to generate green energy, or to pay for the installation of additional renewable generators (e.g. wind turbines).

What’s more, some companies can apparently sell their “green energy” several times (ie sell more than they generate).

In Ireland, we can choose from two electricity suppliers: ESB and airtricity . The latter owns several wind farms and, as a result, claims its electricity is 79% renewable. But, given that all of Ireland’s electricity is distributed down the same national grid, how can airtricity customers know that their supply is indeed 79% renewable?

Does switching to airtricity really help to drive the move to renewables in Ireland, or just make us feel good?

Einstein’s fridge and the Aga cooker

marymulv — Wed, 24 Sep 2008 16:58:00 +0000

I hadn’t known that Einstein had invented a novel type of fridge in 1930, together with Hungarian physicist Leo Szilard. I was even more intrigued to read that engineers at Oxford are reviving their elegant design, because it has no moving parts and is ideal to run on solar power.

The physics fridge uses ammonia, butane and water, rather than freons, and exploits the fact that liquids boil at lower temperatures when the air pressure around them is lower.

The green Oxford physics fridge would be low maintenance and ideal for rural locations, but it’s still at the prototype stage.

The news reminded me of another kitchen appliance invented by yet another Nobel physicist: the Aga cooker was the brainchild of Swedish physicist and inventor Gustaf Dalén in the early 1900s.

He set out to make an energy-efficient, multi-purpose cooker that could be used for baking, boiling, grilling and warming, and that would need little watching or attention. Aga, by the way, stands for Aktiebolaget Gas Accumulator

What’s green, and earning money?

marymulv — Mon, 22 Sep 2008 16:11:00 +0000

Expect to hear more about the Danish island of Samsø which, thanks to a massive community effort over the past decade, is now self-sufficient in renewable energy.

The 4,000 inhabitants spent €54 million (raised in local taxes and investment), to install nearly a dozen wind turbines on land, and the same again offshore, plus banks of solar panels, and some biomass generators.

The scheme has been so successful it is selling electricity to the mainland and generating an income for the locals — albeit about €68 per household a year.

Shows what can be done. Looks pretty idyllic too – we predict a boom in ecotourism there.

Irish firm makes CleanTech top 100

marymulv — Thu, 18 Sep 2008 10:44:00 +0000

An interesting list of the ‘companies of the future’ has just been published by the Guardian and Library House. It spotlights 100 private firms around the world working to develop new clean, renewable and sustainable technologies.

Interesting to see Irish firm OpenHydro tipped among the 100 hottest to watch.

The Dublin company, one of only a few picked out in the marine power section, was selected for its innovative turbine design. This is already generating power off the Scottish Orkney Islands, and the four-year-old company plans to be the first in Britain or Ireland to produce tidal power for the National Grid.

The full 100 listing makes for interesting reading — as might be expected, rather a lot of German companies listed, but also quite a lot of British firms (surely not a national bias there?!)

Misleading energy ratings

marymulv — Tue, 24 Jun 2008 17:54:00 +0000

Buy A-rated electrical appliances, we are told, because they are more energy-efficient.

Not so, says Brendan Boardman of the UK’s Environmental Change Institute, writing in the latest edition of Chemistry & Industry magazine. It seems that it is easier for larger devices to achieve an A-rating, even though they consume more electricity on average than smaller ones. The problem arises because energy levels are calculated on relative values (kWh/litre).

The net result is that manufacturers make ever bigger appliances, and consumers are encouraged to buy them.

Moral of the story? Remember that every appliance has two price tags: the purchase price, and the price you will pay for all the energy it will consume during its lifetime. And an A-rated appliance is not necessarily the best buy, financially or environmentally. Caveat emptor.

Electricity use and prices soars

marymulv — Wed, 18 Jun 2008 13:27:00 +0000

Bad news but also some good news in yesterday’s report from Sustainable Energy Ireland on our soaring electricity use, and the ESB’s application for a 30% increase in the price of electricity.

First the bad news. There are nearly 1.5 million households in Ireland now (up 43% since 1990); our homes are larger on average than elsewhere in the EU, and thanks to the boom years of the Celtic Tiger, packed with power-hungry appliances such as American fridges and large-screen plasma TVs, and constellations of recessed lights. We are also heating our homes more than before — a toasty 6° warmer than in 1970, if UK trends also hold here.

The net result is that Irish people are now using 62% more electricity per person than in 1990; which is a staggering 27% more than our British counterparts, and over 30% more than the EU average. We are a small country, but clearly punching way above our weight when it comes to consumption and emissions.

The good news? Well, if British households can survive on significantly less electricity, then there may be hope for us. And while no one likes to see electricity bills rise by 30% — especially with 10% of households already experiencing ‘fuel poverty’ — a price hike might prompt us all to economise. More effective at reducing consumption than the government’s promised ban on incandescent lightbulbs. Maybe we could start by turning the thermostat down 6° — back to 1970?!