Is there such thing as green electricity?
Home » Magazine » Good, issue 11 » Is there such thing as green electricity?You can buy power from a company that makes renewable energy, but the electricity you actually use won’t be squeaky green. Powershop’s Ari Sargent explains why—and what you can do about it
New Zealand is privileged to be able to generate 70 percent of its energy from renewable resources, but the complex web of electricity generation and supply means green electricity consumption isn’t as simple as choosing your power provider. Going with a company that generates solely renewable electricity is a good start, but when you turn on a light the power is still tinted brown by 30 to 35 percent of the country’s fossil-fuel-generated power.
That’s because all generators in New Zealand are required by law to sell their energy to the country’s wholesale electricity market. All power stations connect to the national grid, and electricity retailers buy energy from this wholesale market and sell it to customers. That means there’s no direct link between the company you buy your power from and where it’s actually produced. Even power retailers that also generate electricity cannot guarantee you are buying the power they produce.
It’s like pouring a bottle of pure mineral water into the Waikato River. If you fill that empty bottle with water a kilometre further down the river, it’s obviously not going to be as pure as the bottle of Evian you originally tipped in.
Meridian generates only renewable energy, but the energy it buys from the wholesale market to sell to its customers is a mix of electricity sourced from hydro, geothermal, wind, coal and gas generators. Therefore, even if you buy energy from a retailer specialising in renewable resources, there will still be carbon emissions associated with your power consumption. It’s not possible to track electricity flows through the grid, because electricity obeys the laws of physics rather than the laws of commerce!
The amount of renewable energy that New Zealand produces is higher than that in most developed countries. We are blessed to have water, geothermal and wind resources we can use to generate power. But when it doesn’t rain and the wind doesn’t blow, we rely more heavily on coal and gas. Unless you’re lucky enough to heat and light your house with home-generated renewable sources, such as solar power, then no matter whom you buy your power from, if it comes from the national grid it ain’t green.
There’s no real pattern to the ratio of renewable energy to fossil fuel energy available at any one time. There is seasonal variation, with more fossil fuel energy used in winter to meet higher heating demands, and to ensure there’s enough water left in reserve as a buffer against low inflows. So it makes sense to dial up your electricity conservation efforts in winter. However, over the course of a year, there is a finite amount of hydro inflows; it won’t rain any more or any less because of how much power you use. This means that conserving electricity use at any time of the year will normally reduce fossil fuel generation overall.
To use less electricity, you need to know how much you use to begin with. Reading your meter daily will give you some idea, and it’s gratifying to see the units slow down as you remember to do things like switch off appliances at the wall. Effective insulation is becoming an increasingly popular way of making homes more energy-efficient. While there is an initial set-up cost, home-heating bills can be sliced by up to half.
If you’re committed to reducing your carbon footprint, buying power bundled with carbon offsets is the next best alternative to using less power. Airshed Energy and PowerKiwi both sell carbon-offset power through Powershop. These companies offset the estimated carbon emissions associated with household electricity use through supporting renewable energy and energy-efficiency projects in developing countries. Initiatives include solar housing in India, biogas plants in Nepal, wind farms in Madagascar and organic composting projects in Bali.
All carbon-offset projects must be ‘additional’, meaning the project or initiative producing the offset would not have occurred without the revenue from the sale of the carbon credits. Carbon-offset power is a couple of cents more expensive per unit than other power, but it’s much more cost-effective than buying separate carbon offsets.
It is still vitally important that renewable energy generators and retailers are supported. With ten percent of the nation’s power still coming from coal and around 24 percent from gas, more investment in renewable resources is needed to further limit power supplied by polluting generators.
Fri June 04, 2010 @ 07:06 PM
