Renewable Energy Versus Non-Renewable Energy

1. Where does our electricity come from?
2. What is green power?
3. What is renewable electricity?
4. What is Eco-Logo^M Certification?
5. What impact does conventional electricity generation have on the environment?
6. Isn't hydroelectric power green?
7. Does hydroelectric power generation produce greenhouse gases?

1. Where does our electricity come from?

Canadians refer to electrical power as "hydro". Our electrical utilities for the most part have hydro as part of their name, but just because we call it "hydro" doesn't mean it comes from water. Approximately 99% of the power generated is considered to be non-renewable. Increasingly, electrical power is being generated in Canada by burning fossil fuels.

In fact less than 1% of the power generated in Canada today is considered to be renewable or green power. And, since rivers are a finite resource, there is a limit as to how much large hydroelectric power that we can develop.

The Canadian Electricity sector accounts for 20% of all greenhouse gas emissions.

2. What is green power?

Green power is most commonly defined, world-wide, as renewable low-impact electricity, from renewable energy sources that have low adverse environmental impacts relative to conventional large-reservoir hydroelectricity generation and other non-renewable sources, such as generation from fossil-fuels and nuclear power.

3. What is renewable electricity?

Renewable electricity is produced from energy sources that are replenished naturally or through sustainable management practices, and are not depleted (at current levels of consumption).

Less than 1% of the power generated in Canada is considered to be renewable. Most of the hydroelectric power generated in Canada is not renewable.

4. What is Eco-Logo^M Certification?

In Canada, the criteria for low environmental impact are set under Environment Canada's Environmental ChoiceM Program (ECP). Most provinces, utilities and the green power industry use the ECP-criteria.

The ECP also provides certification and recognition with the Eco-Logo^M for green power generating facilities and electricity products.

Sources of green power are wind, small hydro (typically run-of-the-river), solar, tidal, geothermal, biogas-fuelled and biomass-fuelled power sources, where the sources meet the ECP-criteria for environmental performance.

Not only do green power operations have little or no greenhouse gas emissions, but also other air pollutant emissions which cause smog, acid-rain or toxic pollution are zero (or in the case of geothermal, biogas and biomass-fuelled sources, are controlled within specified limits). Impacts on ecosystems, such as might occur from flooding or variable water flow in hydroelectric operations, or from the effluent or waste ash from biogas and biomass-fuelled sources, are much smaller when compared to conventional electricity generation.

Environment Canada views green power as a preferred option for new and replacement electricity generation. Many utilities choose to generate a portion of their electricity as green power as part of their environmental leadership, or due to provincial policies.

Environment Canada also supports green power retail markets as a way to enable consumers to exercise their own choice for green power through their purchasing power. In fact, Environment Canada started customer choice of green power through its purchase of wind power in Alberta in 1997, the first purchase of green power in Canada.

Many corporations and provincial and municipal governments are also showing their leadership by buying some of their electricity as green power. The Government of Canada seeks to partner with provincial, territorial and municipal governments and with larger private organizations, to increase green power purchases in Canada. So far, about 20,000 Canadians and Canadian organizations choose to buy green power.

While green power currently makes up only a small percentage of Canada's electricity, Canada's green power resource potential is enormous and can lead to substantial reductions of greenhouse gas and other air pollutant emissions from conventional electricity generation.

5. What impact does conventional electricity generation have on the environment?

Electricity generation is one of the primary contributors to air pollution and greenhouse gas emissions. In fact, conventional, electricity generation produces causes more air pollution than any other industry.

Canadian power plants produce:

• Pollutants that result in acid rain
• Most of our nuclear waste
• 20% of our global warming pollution
• Over a third of the air pollutants produced are a chief cause of respiratory-related hospital admissions for children and senior citizens.
  

6. Isn't hydroelectric power green?

Most of the hydro electric power in Canada comes from large hydroelectric power plants built by damming up rivers. Large hydroelectric power plants can have significant impacts on the environment and are no longer considered to be green. Only small run-of-river power plants (those installed without damming up streams and rivers and below 30 MW are considered to be green or renewable energy sources.

The environmental impacts of large hydroelectric power plants include:

• The disruption of natural river flows;
• Alter or destroy river and riverside habitat;
• Negatively impact water quality;
• Disrupt fish spawning;
• Prevent the natural flow of sediments;
• And as recent studies have pointed out:
• Release significant quantities of greenhouse gases, especially methane which is 20 times more potent than carbon dioxide.

7. Does hydroelectric power generation produce greenhouse gases?

Yes, in fact recent studies have determined that the flooding of large areas of land causes a lot of greenhouse gases to be released.

Far from being "green," many hydroelectric power plants release more greenhouse gases into the atmosphere than large coal-fired power stations. This is because of the rotting vegetation in the reservoir. According to World Commission on Dams, a group of scientists, engineers and environmentalists supported by the World Bank, the world's biggest financier of large dams.

It was thought that the release of greenhouse gases only occurred after construction, when the decay of forests submerged when the reservoirs fill up creates "only a fraction" of the greenhouse gases. But it is now being discovered that organic matter washed into a reservoir from upstream generates a lot of the greenhouse gas. Also, when draw-down occurs when water is used for power generation, that vegetation will grow in the area exposed. When the reservoir fills up, the flooded vegetation decays and produces greenhouse gases as well. With respect to a large reservoir with thousands of miles of shoreline, this is a significant amount of vegetation. This means that the emissions don't disappear when the initially flooded forest has rotted away, but will continue for the lifetime of the reservoir.

Hydroelectric reservoirs cover an area of the world the size of France. They release carbon dioxide and methane. Stagnant water produces the worst emissions because the decaying vegetation generates methane. This is 20 times as potent a greenhouse gas as CO2, which is produced when there is oxygen in the water. So a reservoir will produce more methane than the river did before the dam was built.

Warnings about greenhouse gas emissions from reservoirs surfaced in the mid-1990s. But what appeared at first to be a problem for a handful of reservoirs now looks much more general.

"Tropical reservoirs that are shallow and not cleared of biomass [before flooding] appear most at risk," says the commission. It names two rainforest reservoirs as major planet-warmers. One is Balbina in Brazil, which is just 12 feet deep in parts. Its generating capacity is 112 megawatts and it is estimated that it will produce 3 million tons of carbon per year over its first 20 years. A coal-fired power station of the same capacity would produce 0.35 million tons per year. Petit-Saut in French Guyana, which has a similar capacity and powers the launch site for Europe's Ariane rocket, will produce 0.9 million tons per year in its first 20 years.

The report's authors have only studied a handful of reservoirs so far, in just four countries, so they believe there may be many more offenders. "Greenhouse gases are emitted for decades from all dam reservoirs in the boreal and tropical regions for which measurements have been made. This is in contrast to the widespread assumption that such emissions are zero," says the commission. "There is no justification for claiming that hydroelectricity does not contribute significantly to global warming."

Jamie Skinner, environmental adviser to the commission, which is based in Cape Town, South Africa, says the report is significant because both dam engineers and environmentalists agree on its conclusions.