The
Electricity Conservation and Supply Task Force commissioned by the McGuinty
government reported in January ’04 that even if we adopt “aggressive”
conservation measures the withdrawing of coal fired generation by 2007 and the
retiring of nuclear generating plants as they come to the end of their lives (a
total of 80% of generating capacity) Ontario will have a shortfall of about
25,000 megawatt (MW) by the year 2020. Energy Minister Dwight Duncan in
speaking to the Empire Club of Toronto April 15, ’04 estimated that replacing
this generating capacity would cost between 25 and 40 billion dollars.
This
proposal looks in a preliminary manner at the possibility of supplying the
entire anticipated shortfall of generating capacity with wind turbines. Wind as
an energy source is clean, renewable and free. But constant the wind is not.
Where wind energy is well established as in northern Europe, other forms of
energy such as from fossil fuels are required to take up the slack caused when
the wind is not strong. In North America at this time wind energy supplies such
a small proportion of the total electrical output that it can enter the grid
with little effect. If, however, we are to build a system that relies mainly on
wind energy, we need to have a back up for when there is no wind. Contrary to
conventional thinking we do not need to build nuclear and/or fossil fuel fired
generators as backup. This is where our unique geography can make the
difference.
Lake
Ontario, the lowest of the five Great Lakes, is 99 meters below Lake Erie.
Water falling into Lake Ontario at Niagara has given us cheap and clean
electricity for almost a century. The potential of the relationship of these
lakes has, however, not been fully realized. Not only can we benefit from water
that flows naturally, we can pump water back up from Lake Ontario to Lake Erie
when we have a surplus of power at night and weekends and draw it down when
electrical loads peak such as in the coldest part of winter or in a heat wave
in summer. There is already some pumping up of water from Lake Ontario into a 3
square kilometer pond above the Adam Beck generating station on the Lower
Niagara River and the technology is familiar. Lake Erie with an area of 25,720 square kilometers is 8,470 times
larger in area than the pond. Lake Ontario is only slightly smaller. The pond
in relation to Lake Erie is as a drop in a bucket.
The
ability to raise a large volume of water a substantial height from one enormous
lake to another enormous lake with little effect on the water level in either
gives us a scale of energy storage potential found nowhere else in the world.
The Cost of the Wind Turbine
Component
Generating capacity must exceed peak loads to avoid importing energy at high cost. In estimating the number of wind turbines needed we can count on hydro electric power using water previously pumped up into Lake Erie to take care of the peak load requirement. We shall then arrive at the wind power requirement and its cost by meeting the energy requirement rather than the peak load requirement. The peak load requirement and cost will be largely met by the “backup” facility shown later.
In 2002 Ontario Power Generation (OPG) generated 115.8 terawatt-hours of electricity or 317 gigawatt-hrs per day on average. (With a capacity of 22,733 megawatts it could have produced 24 x 22,733 = 545 gigawatt-hrs of energy/day. The average utilization factor was therefore 317/545 = 58%. )
Ontario also imported 7% of its electrical energy for a total consumption of 123.9 terawatt-hours. Of Ontario’s production, 71% or 88 terawatt-hours came from nuclear and fossil fuels. Water power supplied about 27 terawatt-hours.
Ontario’s
population is expected to increase to about 15 million by 2020, an increase of
25%. If the per capita rate of energy consumption per capita remained constant,
by 2020 we would consume 154.9 terawatt-hours/year. With realistic pricing,
smart metering, better technology and incentives we can reduce that by half to
about 77.4 terawatt-hours/year. A number of authorities on energy can show that this
is possible.
If
the existing hydroelectric production of 27 terawatt-hours/year is increased to
30 terawatt hours/year together with other green energy, the wind power
objective will then be 77.4 – 30 = 47.7 terawatt-hours/year.
A 1 megawatt wind turbine running at full capacity 24 hours a day for 365 days could deliver 8760 megawatt-hours/year, but because the wind is often calm, each such turbine will on average deliver less than this, about 2,600 megawatt-hours/year or 0.0026 terawatt-hour/year. The requirement is then 47.7/0.0026 = 18,300 wind turbines approximately. In recent contracts for wind energy the cost per megawatt has been about $1.77 million. Total cost of wind turbines would therefore be about $1.77 million x 18,300 = $32.5 billion. This volume of purchases will probably result in lower costs.
The Cost of the Stored Hydro
Power Component, the “Backup”
Whenever there is more electricity generated by the wind than there is demand, water will be pumped from Lake Ontario to Lake Erie. Allowing a 28% loss for pumping up from Lake Ontario results in a Lake Erie water storage utilization factor of 0.72. Losses due to evaporation will be small since the water pumped up will soon be drawn down again.
To estimate the cost of the additional hydro electric generator/pumps required assume that on a hot but calm day in summer (probably the worst case) the output from the wind turbines drops to 20% of rated 18,300 megawatt capacity. The remaining 80%, or 14,600 megawatt, must come from the new hydroelectric generators. The estimated cost in June of 2004 of the proposed Beck 3 generators, was $1.633 million/megawatt including a new tunnel to bring water from Lake Erie. The cost of providing 14,600 megawatts of new hydroelectric generating capacity taking into account the 0.655 utilization factor stated earlier would be 14,600 x $1.633 x 1/.72 million = $33.1 billion.
Total Cost
The estimated cost over 15 years to meet the projected shortfall of electrical generation in Ontario would be $32.5 billion for the wind turbines + $33.1 billion for the hydroelectric generators = $65.6 billion.
Although this is an enormous cost and is about twice the recent projected cost of
nuclear power generation over the same time period, the past record of nuclear generating costs suggests that recent estimates may not be realistic The lifetime of nuclear facilities has been disappointing whereas that of wind turbines has not.
The
following calculations will quantify the potential storage in Lake Erie and
show how small a variation of lake levels is needed to supply the required back
up energy.
When
1 cubic meter of water, weighing 1000
kilograms falls through a distance of 98 meters, the gravitational energy
change is 960400 joules. If this takes place over a time of 1 hour, the power
is 960400 joules / 3600 seconds or 267 watts. If the efficiency of conversion
of gravitational energy into electrical energy is 95%, the electrical power
derived from 1 cubic meter of water is 0.95 x 267 = 254 watts or 0.000254
megawatts.
Therefore
to generate 14,600 megawatts will require 14,600/0.000254 = 58 million cubic
meters per hour. In one day 58 x 24 = 1392 million cubic meters of water would
be drawn down.
The
area of Lake Erie is 25,720 square kilometers. The volume of 1 cm. of height at
the surface of lake Erie is 257 million cubic meters. When 1392 million cubic
meters of water is withdrawn the lake will drop 1392/257 =5.4 cm. Should a
similar storage strategy occur on the U.S. side of the lake, the variation in
lake level on account of both countries would be 10.8 cm. an amount that would
seem acceptable.
Nobody wants to see the level of Lake Erie lowered in order to produce electricity. This proposal requires no permanent lowering of the lake level. The water transfer should be thought of like a charge account, not a credit account. The draw down from Lake Erie should never be more than the amount previously put into it using surplus wind power.
The NIMBY (not in my back yard)
Problem
If all turbines were of the 3 MW size, 6,115 of them would be required.
No one but the most ardent wind aficionado wants a windmill in his or her backyard. Situating them in Lake Erie and in shallow waters at the eastern end of Lake Ontario is one solution; objections to the sight and sound would be minimized. Virtually all new wind turbines to be built in Denmark, a leader in wind power, will be in coastal waters. The cost is a little higher but this is offset by the stronger winds over waters. Lake Erie is relatively shallow which makes the cost of installation reasonable. Another desirable location with steady winds is Wolfe Island at the eastern end of Lake Ontario and shoals to the west of the island.
Wind turbines need to be spaced far enough apart so that they do not interfere significantly with the wind each of them will receive. A wind farm requires about 0.065 square kilometres per MW of generating capacity. If we require 18,346 MW of capacity, the area of wind farms will need to be 0.065 x 18,300 = 1,190 square kilometres. The area of the Canadian side of Lake Erie is 12,800 sq. kilometers. Even if all the wind turbines were placed in Lake Erie, the area affected would only be 9.3 % of the lake. In areas with a depth of up to 15 meters, a depth presently considered economical, there is about 580 square kilometres, enough for about 9,000 MW, nearly half the requirement. Research into siting in deeper waters is underway in other countries so that locating the majority of wind turbines in Lake Erie is a distinct possibility.
Advantages of Massive Wind
Power with Great Lakes Storage
· Zero fuel cost
· Operating cost predictability
· Investor security
· Short delivery time
· No green house gas emissions
· Large contribution to Kyoto obligation
· No nuclear spent fuel disposal costs or dangers
· End of life recycling value instead of enormous cost of burial of entire nuclear facility
· No target for terrorists
· Minimal added distribution costs
· Close to usage, minimal distribution losses compared to imported power
· Large new industry with long term demand for product
· Long term R & D potential
· Large export potential
· Steady income to farmers for land based turbines
· Unaffected by drought
Disclaimer
The intention of this proposal is to stimulate discussion about our energy needs.
Most of the above calculations are based on information taken from the web. As I am no authority on wind power, electrical energy, or finance, I hope that people with expertise in these areas and with more accurate information will examine this proposal and advise me of any serious errors, or perhaps come forward with better proposals.
201
Westdale Ave.
Kingston,
ON, K7L 4S4
Phone
(613) 542 4045
Email: bubbleactionpumps@cogeco.ca