Energy BOT Squad’s Newest Member

Energy doesn’t get much more underground than geothermal power, which unlocks the heat trapped below the surface of the earth. But when it comes to Canada, geothermal energy is still “underground” in more than a few ways — just ask GeothermalBOT.

At the moment, GeothermalBOT mainly has to keep himself warm using the heat pumps that use the differences in temperature between the ground and the air to cool or heat homes. They’re small and localized, and the only game in town for a BOT that wants to keep nice and toasty. In fact, there aren’t currently any large geothermal power plants in Canada. But that doesn’t mean that GeothermalBOT will be stuck in Canada’s energy underground for the rest of his days.

In fact, Canada has considerable geothermal potential, with near-surface resources found across the country in areas as far apart as British Columbia and Saskatchewan. There has even been talk of developing these resources — just look to the Canadian Geothermal Energy Association (CanGEA) — though so far Canada still has no geothermal plants. Around the world, though, it’s a slightly different story.

To find areas where geothermal power has already heated up, GeothermalBOT would need to take a look at Iceland, where geothermal plants produce almost a quarter of the country’s total electricity. Because of the area’s high concentration of volcanoes and other heat sources near to the surface of the earth, the country has a natural wealth of geothermal energy that it’s used since 1908, when a farmer piped in water to heat his home. Other countries that use geothermal energy include the US, the Philippines and Indonesia.

But GeothermalBOT’s not likely to be heading to Reykjavik any time soon. For now, he’s fine being part of Canada’s energy underground, because a nice hot water tank is still a fine place to spend your time.

Turning Yucky Stuff into Energy – It’s a Gas

Two things we try to avoid stepping in are garbage and manure. Yet, disgusting as they may be, these two members of the biomass clan are sources of renewable energy. Just not in their usual forms.

Take garbage. Day after day it is trucked out to huge landfills where it gets buried by more garbage. As the trash piles up, the lower layers become starved of oxygen and the conditions near the bottom of the heap become anaerobic, allowing anaerobic bacteria and other microorganisms to feast on the garbage, creating landfill gas, a mixture of methane and carbon dioxide.

Once a landfill is full, it is usually capped by thick layers of dirt and often a sealing membrane, and left to sit, while more landfill gas accumulates. Finally, collection wells are drilled and cased to the base of the landfill. The section of the casing penetrating the waste layers is perforated so the landfill gas can enter the pipe. Unlike natural gas wells, landfill gas must be pumped out of its reservoir.

Agricultural wastes such as manure, crop residue, and silage are collected in a digester, a large, domed tank, often built underground. Again, as the waste accumulates, the lower section becomes oxygen-starved and anaerobic microbes acting on the waste produce methane and carbon dioxide. Because the material in the digester is a thick liquid slurry, the biogas rises to the top of the digester where it can be siphoned off. Once the slurry has been digested, the residue can be used as fertilizer.

With both processes, the carbon dioxide must be removed before the biogas can be used as fuel. Biogas can be used as a substitute for natural gas in fuelling electricity generation, space heating, and natural gas powered cars and buses.

Biomass – Now It’s Renewable

Image: E-ON UK

For a long time, people equated wood and peat with coal – burning all three released a lot of carbon dioxide (CO₂) into the atmosphere. And that is bad.

But, on sober second thought, wise people realized that coal has been buried for millions of years, and as long as it remains buried and isn’t on fire, it doesn’t emit CO₂. On the other hand, trees and peat are growing plants that trap CO₂ when they are alive. When they die, the trapped CO₂ is released. And, here’s the important part, the same amount of CO₂ is released whether the material decomposes naturally or whether it’s burned. Consequently, wood and peat and other biodegradable substances are carbon neutral. And that is good.

Burning carbon neutral material for fuel is better than burning something that will emit new CO₂ into the atmosphere, or if not new CO₂, CO₂ that’s been out of circulation for millions of years.

Most of the wood burned in Canada is fuel for space heating and is burned in residential woodstoves and fireplaces. However, Canada has a large forestry industry that harvests trees for wood and pulp and paper products. Many forestry companies collect the wood residue from harvesting trees and from sawmills and paper mills and burn it to provide electricity for their operations. And many of these generate more electricity than they need, so they sell it back to the grid.

In fact, the Canadian Industrial Energy End-Use Data and Analysis Centre estimates that the energy capacity of wood residue in Canada is 1.4 megawatts for electricity and 3.6 megawatts for heat, and in 2008, biomass fueled generation of 9,829 gigawatt-hours of electricity.

Canada also has the largest peat reserves in the world, roughly 45 per cent of global supply. Peat bogs are found in every province and territory, with the majority being in Northwest Territories, Ontario and Manitoba. However, Canada does not use peat as biomass fuel for commercial generation of electricity.

Maybe it’s time we did.

Investing in More than Just Infrastructure

Electricity is important to Canadians. It not only powers Canadian homes and businesses, in 2010 it contributed about $25 billion to the Canadian economy and provided more than 100,000 jobs. However, according to the Conference Board of Canada, approximately $293 billion need to be spent on infrastructure over the next 20 years to keep the current flowing.

Capacity growth was biggest in the 60s and 70s, averaging about six percent per year. In the 80s, this dropped to 2.9 per cent and decreased further in the 90s and 2000s to 0.5 per cent. And while infrastructure investment has been at record levels the past few years, it has gone more toward maintaining capacity and not to increasing it.

Between 2010 and 2030, $195.7 billion will be needed for capacity-building projects to either refurbish existing generating facilities or replace retired ones. About two-thirds of that will be spent in three provinces:

Province	Requirement	Purpose
Ontario	$60 billion	Refurbishment, retirement, Feed-in Tariff program
Alberta	$44 billion	Oil sands expansion, replacing coal-fired generation
Quebec	$29 billion	New wind projects, hydro refurbishment

 

But it’s not just generation projects that are needed. Transmission and distribution projects account for about one third of the budget. Of the $36 million in transmission investment, 72 per cent will be spent in three provinces:

Province	Requirement	Purpose
Alberta	$17 billion	North-south interconnections
Ontario	$5 billion
British Columbia	$4 billion

 

Distribution projects account for $62 billion of new investment, with three provinces spending about 87 per cent of the distribution total:

Province	Requirement	Purpose
Quebec	$22 billion	Distributed generation, smart meters, changing electricity requirements.
Ontario	$21 billion
Alberta	$11 billion

 

It may seem like a high price to pay, but the expenditure is going towards updating or replacing old, inefficient generating facilities, many of which are coal fired, and building more efficient renewable generation. In the long run, it’s a worthwhile investment.

Energy BOT Squad’s Newest Member

This week we’re heading out into the field to find the most rustic member of the Energy BOT Squad: BiofuelBOT. Powered by biofuels that can be produced from sources like corn, cellulosic crops and even waste from the lumber industry, he’s a BOT who can pretty much consume anything.

Energy from biomass is actually not a new concept. In fact, burning wood to produce heat and light is the oldest form of biomass energy. But modern technologies like wood pellets have changed the way we make that fire, compressing the waste from pulp and paper mills into tiny, intensely burning pellets. In British Columbia, where the lumber industry has had to face the scourge of mountain pine beetles, wood pellets are even part of the province’s energy plan. But even a tough BOT like BiofuelBOT has to leave the forest sometimes.

Biomass energy also includes the creation of more complex biofuels, like ethanol and biodiesel. These fuels, in turn, can be mixed into conventional gasoline or used by themselves. They’re created using either primary feedstocks, which can include crops like corn or fibrous, “cellulosic” crops like switchgrass, or secondary feedstocks, like the waste from lumber mills. These feedstocks are then processed in a variety of ways, usually through chemical or biochemical conversion, but the result is the same: fuel that lets BiofuelBOT cruise the open road.

And when it comes to waste, BiofuelBOT is always willing to step in and take a bite, because a tough BOT is a hungry BOT. Landfill gas facilities take the methane produced by decomposing garbage and pipe it into a thermal facility capable of burning the gas to produce electricity. And since secondary feedstocks can include nearly any biological source, from cow manure to shrimp shells, there’s really not much that BiofuelBOT can’t eat.

Around the world, just as in Canada, bioenergy is used for both heat and electricity. Large plants include California’s Altamont Landfill liquefied natural gas facility, which can produce up to 13,000 gallons of liquid natural gas per day, and the recently opened biodiesel plant in Singapore, the world’s largest with a capacity of 800,000 tonnes a year. And expect BiofuelBOT to keep on spreading his rustic charm, because with an appetite as wide-ranging and tough as his, BiofuelBOT’s always got something to chew on.

The Passive Side of Solar

Not that solar PV and concentrating solar power are aggressive. They’re active, and passive solar is more easy-going, don’t worry about electronics or mechanical devices; just let the sun do all the work.

Like its more active cousins, passive solar begins with design. Situate a building; let’s say a house, to take advantage of natural sunlight and natural air currents. That way, the house benefits from warmth and ventilation. Put lots of large windows on the south-facing wall (if you live in the Northern Hemisphere, north-facing wall if you live in the Southern Hemisphere), and maybe a deciduous tree or two outside the windows. Build the roof with a large overhang. Provide some sort of thermal mass, like a tiled concrete slab floor or a brick wall. And that is basically it. Sit back. Relax.

In the summer, when you really don’t need the heat, the sun is directly overhead and the overhangs and trees prevent direct sunlight from coming through the windows. In the winter, when you do need the heat, the sun is lower in the sky and the trees have shed their leaves, and sunlight comes directly through the windows, warming not only the room, but also the thermal mass. Once the sun sets, the thermal mass releases its absorbed heat to the room, reducing the need for furnace heat.

Let’s say you’ve done all this but when you stand back and look at your house, you think “Gee, the south-sloping roof looks bare, but I don’t want solar PV panels and all the wiring and batteries they entail. What can I do?”  Well, you can consider a solar collector. Solar collectors consist of piping that is surrounded by dark, heat-absorbing material overlain by a transparent film or glass to avoid heat loss and backed by insulating material, again to avoid heat loss. The heat-absorbing material transfers its heat to a fluid circulating through the pipes that run into the house. The fluid, in turn, transfers its heat to a heat sink such as a water tank or thermal wall to be used for water or space heating.

With passive solar, the only work you’ll need to do is open the curtains. And close them at night; they make a good thermal barrier.

PVs, Troughs and Towers – Electricity from the Sun

When we think of solar powered electricity, the image that usually comes to mind is one of solar panels on the roof of a building. Solar panels consist of many connected photovoltaic (PV) cells which are made mostly of silicon with other compounds. When light energy strikes a PV cell, some of the energy is absorbed, freeing electrons which then form an electric current.

Solar panels are most often used in small applications, such as providing electricity for a house or similar sized building. However, there are now solar parks, similar to wind farms, where large arrays of solar panels provide power to electricity consumers. The largest such solar park is the 80 megawatt Sarnia Solar Project, pictured here, in Sarnia, Ontario.

Image: Enbridge

The overall efficiency, from panel to grid is about 15 per cent.

The other way to produce solar electricity is through a process known as concentrated solar power. Lenses or mirrors are used to focus sunlight on a small area to heat a liquid which flows through a heat exchanger creating steam to run a turbine. The two most common forms of concentrated solar power are parabolic troughs and solar power towers.

Parabolic troughs are, as the name suggests, troughs with reflecting surfaces in the shape of a parabola. The suns rays are focused by the parabola onto a pipe running the length of the trough. A synthetic oil in the pipe heats to 350 °C and is used to make the steam that runs the turbine. Efficiency is similar to that of PV cells.

Solar power towers consist of a field of mirrors which concentrate light on a receiver located atop a tower at one end of the array. The receiver heats a fluid that provides the heat for steam generation. Overall efficiency is slightly better than that for parabolic troughs.

HAWTs and VAWTs

There are two basic types of wind turbines defined by the orientation if the axis or drive haft that turns the generator – horizontal axis wind turbines (HAWT) and vertical axis wind turbines (VAWT).

Horizontal axis wind turbines are the oldest, most efficient and therefore, the most common of the two types. They consist of two or more vertical blades (three is the most common) attached to a hub which is in turn attached to the horizontal drive shaft and the generator. This whole assembly sits on top of a tower. The blades face into the wind on the windward side of the tower to avoid any disturbance the tower may create. The tower is designed to elevate the blades into the strongest and most consistent wind. Currently, the longest blades are 82 metres long (269 feet) and the tallest towers reach 180 metres or 590 feet.

There are many different vertical axis wind turbine designs, ranging from the Darrius “egg beater” configuration to bladed turbines. Like HAWTs, vanes or blades turn a shaft connected to a generator , although in this case the shaft is vertical and the generator on the ground. There is no tower, and VAWTs  are generally much shorter than HAWTs, The prime advantage of  VAWT configuration is that it faces always faces into the wind, and is therefore better suited to areas where the wind is continually changing direction. Because of their more compact design, VAWTs are commonly used for microgeneration by home, cottage and small business owners and farmers to provide power for their own use or to sell back to grid.

A new development combines a VAWT with solar cells to provide electricity from wind power and solar power at the same time.

Ontario Pours Cold Water on Offshore Wind Farms

Offshore wind farms are viewed as one answer to wind turbine noise, unsightliness, and danger to bats. Makes sense? – put them where no one can hear or see them. As well, offshore winds are far more consistent and reliable than onshore winds. There are more than 40 offshore wind farms in China, Japan and 10 European countries. Their total combined capacity at the end of 2009 was almost 2,000 megawatts. So the question is why aren’t there offshore wind farms in Canada?

The answer is obvious for Alberta and Saskatchewan – neither have an offshore. Sure there are some big lakes but those are well off the grid and the costs of transmission infrastructure and transmission itself would be prohibitive.

British Columbia may soon have an offshore wind farm. On March 17, 2011 NaiKun Wind Energy Group was “granted a federal screening decision, confirming that Canada’s first offshore wind project can be constructed with no significant environmental, social or health effects.”  The project will be located in Hecate Strait Haida Gwaii and Prince Rupert and will comprise up to 110 turbines will a combined installed capacity of 396 megawatts.

Image: Naikun Wind Energy Group

While Ontario doesn’t have a sea coast, it does border on three great lakes: Ontario, Erie and Huron. Until recently four offshore projects were planned, but in February, the Ontario government decided to impose a moratorium “until the necessary scientific research is completed and an adequately informed policy framework can be developed.”  The ministry also said “Offshore wind power development in freshwater lakes is relatively new and presents technical challenges that do not exist in a saltwater environment, such as the need to manage potential impacts to drinking water and the effects of ice build-up on support structures.”

The action be the Ontario government seems to be counter to its previous assertions that wind power will be a more and more important source of electricity as the province’s coal-fired generating stations are phased out.

There is one other example of a wind farm in fresh water, the Vindpark Vänern on Lake Vanern in Sweden. Located 6.5 kilometres off shore and consisting of 10 three-megawatt turbines, the project went on line in May 2010.

While New Brunswick, Prince Edward and Nova Scotia currently do not have offshore wind farms, all three provinces are investigating the possibility.

Wind on a Global Scale

As with pretty much every great discovery, the initial use of wind power was probably accidental. Someone standing on a raft put out their arms, the air current caught their cloak and presto, the wind had been harnessed.

Initially, using the wind was more a case of redirecting it – into sails for transportation, through ducts and pipes for ventilation. Later, some enterprising person figured out how to power machines, like water pumps and grain mills with the wind.

It wasn’t until 1887 that a Scotsman named James Blyth first used wind-generated electricity to light his summer home. Later the same year, Charles F. Brush made a horizontal axis wind turbine that powered his house and laboratory in Cleveland, Ohio.

Left: James Blyth’s vertical axis wind turbine   Right: Charles Brush’s horizontal axis wind turbine.

Wind powered generators grew in popularity, primarily on farms or isolated buildings not connected to the grid. Capacities of these early generators was usually in the range of five to 10 kilowatts.

In the late 1970s, capacities increased to 20 to 30 kilowatts and the market expanded, especially in Europe. In 1980, the first wind farm was built in New Hampshire and comprised 20 30-kilowatt turbines. However, the project failed because of design errors. Never the less, it paved the way for successful projects soon after. The largest on shore wind farm in the world is the Bigelow Canyon Wind Farm in Oregon. The project consists of 217 wind turbines with a combined installed capacity of 450 megawatts. The site covers 100 square kilometres.

The first offshore wind farm was constructed at Vindeby, Denmark. It consists of 11 450-kilowatt turbines with a combined installed capacity of 4.95 megawatts. The largest offshore wind farm is Thanet, off the southeast coast of England. Covering 35 square kilometres, it comprises 100 three-megawatt turbines with a combined installed capacity of 300 megawatts.

Thanet Offshore Wind Farm Image: Vattenfall

The total global installed capacity is more than 200,000 megawatts, and individual turbine capacity has risen to seven megawatts. The top five producers are the United States (28.3 per cent), Germany (14.4 per cent), Spain (13.9 per cent), China (10.0 per cent) and India (6.1 per cent). Canada ranks 13 overall with 1.4 per cent.

In Denmark, wind generation accounts for 18.7 per cent of total electricity generation. Portugal ranks second with 15.5 per cent and Spain ranks third with 12.6 per cent. In Canada, wind power contributes less than one per cent of total electricity generation.

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