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Clean Power Capgemini is one of the world’s foremost providers of consulting, technology, outsourcing services & local professional services in over 40 countries – Photo Courtesy Capgemini

Published on April 28th, 2014 | by Roy L Hales

35

What Can We Do About Grid Loss?

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April 28th, 2014 by  

Originally published in the ECOreport.

A high-power electrical tower – Photo by FASTILY, cc By 3.0, Courtesy Wikipedia Commons

A high-power electrical tower.
Image Credit: FASTILY, CC-BY 3.0 license

The world’s transmission lines are believed to have dropped approximately 1.4 trillion kilowatt-hours of electricity last year. That’s around 1.2 trillion metric tons of CO2 dumped into the atmosphere. Though it is unlikely these loses can be eliminated in the near future, there are ways to reduce them.

Losses of 5–7% or so are the norm today in the United States, BC, and Ontario.

Capgemini is one of the world’s foremost providers of consulting, technology, outsourcing services & local professional services in over 40 countries – Photo Courtesy Capgemini

Capgemini is one of the world’s foremost providers of consulting, technology, outsourcing services & local professional services in over 40 countries
Image Credit: Capgemini

Capgemini, one of the world’s foremost consulting firms, has been working with Ontario Power Generation since 2001. Larry Rousse, Director of Utilities at Capgemini, said, “The approximate amount of Transmission line losses in the Ontario system is 6.5%. Transmission losses do vary pending the demand on the system. Losses occur as a natural phenomenon when electricity is transmitted between two points. The physics of electricity means that losses rise exponentially as the current on a circuit increases. For the electricity grid, this means basically that losses are highest when power consumption or when the demand is the highest.  On an Ontario system with ~29,000 kilometers of transmission line, losses can be over 1000 MW (the size of a Bruce nuclear unit).”

The transmission losses appear to be slightly less on the West Coast. According to Mora Scott, of BC Hydro, they work out to about 5%:

“For fiscal 2013, line losses were 5,159 gigawatt hours, which represents approximately 10 per cent of domestic requirements. These figures are for the total amount of losses and system use, including legitimate technical losses on both the transmission and distribution system as well as theft. Transmission losses represent roughly half of this total and can vary greatly in any given year due to factors such as the volume of energy imported or exported and the amount of energy generated in the plants.”

Utilities engineer Bill Powers says the Sunrise Powerlink, which carries energy from renewable projects to San Diego, loses an average of 7–8% and on a hot day it can rise to as much as 14%.

According to Environment California’s report Shining Cities: At the Forefront of America’s Solar Energy Revolution (p 14), “Many cities depend on electricity transmitted from hundreds of miles away to meet local needs. Roughly 5 to 7 percent of the electricity transmitted over long distance transmission lines is lost. Distributed solar energy avoids these losses by generating electricity at or near the location where it is used.”

“Having the generation as close to the load center as possible, reduces losses due to the reduced requirement to transport generation over long transmission lines,” Rousse said.

Powers has been arguing this for years. He believes that San Diego’s power needs could be satisfied by developing 2/3 of the city’s rooftop solar potential. As only 2% of this potential is presently being utilized, there is a great deal of room for the industry’s expansion.

According to Dave Egles, the founder of HES-PV in British Columbia, the cost of solar now compares favorably with conventional energy.

Solar Panels at Peder Norby’s house in Carlsbad, San Diego – Driving on 100% Sunshine

Solar Panels at Peder Norby’s house in Carlsbad, San Diego – Driving on 100% Sunshine

Southern Californian cities like Los Angeles, San Diego, and San Jose – where the solar panels on some homes produce more power than they need – are leading America’s development of this technology.

Solar has not been as productive in more northern latitudes. Egles said his home, in Victoria’s suburb of Oak Bay, obtains 40% of its energy from solar panels. A house in Kamloops BC draws 75% of its power from solar. Some homeowners in the rain forests of BC and Washington state have been told, of course, that there are too many trees around their houses. They would need to cut them down to increase the amount of available sunshine before considering solar — not a logical option.

Egles said Ontario’s rooftop solar industry has developed to the point that you cannot drive a mile without seeing an array installation, but he did not suggest it could totally replace conventional energy sources.

On page 5 of his 2007 study, The Potential for Solar Electric Power in British Columbia, Egles wrote that rooftop solar could supply 53% of the province’s residential needs.

Environment California claims (p 36) that every one of America’s 50 states has the potential to generate more electricity from the sun than it uses in an average year and in 19 states the solar PV potential exceeds demand by a factor of 100 or more. They include Washington state among those where the potential exceeds demand by a factor of at least five (figure 7).

Only they did not expand upon this topic sufficiently for the reader to know if this an unattainable potential – that might, for example, require the entire nation to be transformed into a solar farm – or an attainable goal.

Every state is said to have more solar potential than demand in Figure 7 from Environment California’s report, “Shining Cities:  At the Forefront of America’s Solar Energy Revolution”

Both Rousse and Scott perceived renewable technologies (wind, PV, hydroelectric, & biomass) as components in a larger picture.

Rousse added that, “Other factors such as volt var optimization (VVO) offer new methods of reducing the voltage or managing the voltage closer to the margin on the distribution systems. Lower voltage levels on the distribution system reduce the overall demand thus having a positive overall affect.”

His company, Capgemini, is helping BC Hydro implement a smart meter system. Scott explained that while this does not prevent grid loss, it will cut down on the amount of wasted energy.

“Normally, BC Hydro pushes out more power from our generating facilities, at increased power loss, to ensure you have quality power when you need it,” he said. “Smart meters provide the final ‘at-the-home’ voltage information that BC Hydro previously did not have access to. This information allows us to manage the amount of electricity delivered from each of our facilities so that we are only pushing through what is needed.”

“While smart meters help to reduce wasted electricity, they do not help us eliminate electricity loss. Loss will continue to increase as demand for electricity increases – line loss is proportional to demand. Also, with or without the smart grid, electricity will still need to be transmitted over long distances and because of this, loss will occur.”

High Voltage LInes in High Voltage Lines over the Columbia River, Washington State, USA. – Jeffrey G Katz, cc by 3.0, en Wikipedia

High Voltage LInes in High Voltage Lines over the Columbia River, Washington State, USA.
Image Credit: Jeffrey G Katz, CC-BY 3.0

This raises another important question. Most electricity is carried through HVAC power lines. In Europe, where Capgemini does a large part of its business, they have been experimenting with HVDC power lines for decades. Power losses are said to be as much as 30-40% lower than with HVAC lines, but this technology also requires rectifier stations that are considerably more expensive.

Scott said, “If BC Hydro were considering expanding our system to transport significant amounts of electricity, BC Hydro would consider HVDC lines as an option. We always evaluate all of our credible options.”

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About the Author

is the editor of the ECOreport (www.theecoreport.com), a website dedicated to exploring how our lifestyle choices and technologies affect the West Coast of North America and writes for both Clean Techncia and PlanetSave. He is a research junkie who has written hundreds of articles since he was first published in 1982. Roy lives on Cortes Island, BC, Canada.



  • Wayne Williamson

    I guess I was surprised by the 1.4Twh or at least 140 Billion Dollars(10 cents a kilowatt hour) loss. Its a large amount of money, but then again I’m sure if you divided it by the territory covered, say take 1 sq mile and see what that takes, it wouldn’t sound so bad. It works out to 37k dollars per sq mile in losses a year. 140,000,000,000/3,790,000=36939..Ok, what about per person. 140,000,000,000/317,000,000=441 dollars wasted per person….

  • Matt

    Can someone answer this for me. I always hear average lose in NA is 5-7%, but “physics of electricity means that losses rise exponentially as the current on a circuit increases” so what percent is lost during peak transmission times? That is what is the lose when running at or above capacity. All those local wires in town with the insulation hanging from them were run above capacity. Except in cases of small deviation, average can be very miss leading.

    • Omega Centauri

      I think exponetially was used as an adjective meaning rapidlyhere rather than its literal mathmatic meaning. Resistive losses go as current squared (a bit more if wires heat up and resistance increases). Inductive losses depend on voltage not current, i.e there is some loss from an energized line even if the current is zero.

    • ken

      electricity-unless generated near use-always has “friction” factor in each step: step-up/step-down transformer–line loss-loss in creation depending on what produces power. perhaps co-generation at use-point can help=using gas to fire boiler/generator giving heat in winter also. co-gen coupled with geothermal could radically cut power use–BUT also profit for companies. Updraft wind generators could join that and b topped off by solar. Updraft wind produces all the time despite surface wind. and solar/stirling experimental generators r at 40% efficiency–=-WE have the means-NOT the WILL.

  • sault

    A comment on the Greentech Media article (the one concerning the huge 1.2T MT CO2 emissions due to line losses….more on that in a minute) was highly illuminating. I hope “GentrifierNumber6″ doesn’t mind me quoting them at length:

    “The fundamental problem with increased efficiency on the transmission grid is that the Investor Owned Utilities lose money when they increase efficiency. All those wasted MWs are subject to a rate of return, so an IOU benefits and ratepayers/citizens pay for electricity that never reaches its destination. IOUs have fought against more efficient transmission for years, often claiming that the technology isn’t reliable, or offering up other canards that have been disproved by years of performance (overseas, in particular) of more efficient conductors.
    Until the PUCs give the IOUs a carrot or beat them with a stick, this will continue to be the case. Strangely, this is also an ongoing policy problem because most RES/RPS that have portions that can be met through “negawatts” have limited efficiency by definition to losses on the distribution grid, rather than the transmission grid.
    The fundamental problem with increased efficiency on the transmission grid is that the Investor Owned Utilities lose money when they increase efficiency. All those wasted MWs are subject to a rate of return, so an IOU benefits and ratepayers/citizens pay for electricity that never reaches its destination. IOUs have fought against more efficient transmission for years, often claiming that the technology isn’t reliable, or offering up other canards that have been disproved by years of performance (overseas, in particular) of more efficient conductors.

    Until the PUCs give the IOUs a carrot or beat them with a stick, this will continue to be the case. Strangely, this is also an ongoing policy problem because most RES/RPS that have portions that can be met through “negawatts” have limited efficiency by definition to losses on the distribution grid, rather than the transmission grid.”
    The 1.2T MT CO2 from line losses is plainly bunk. Human CO2 emissions are 36G MT CO2 annually. Even if it was all from the power sector, 7% of that figure is 2.52G MT CO2. However, electricity only accounts for around 30%-40% of CO2 emissions, so the correct figure for CO2 emissions due to line losses is probably 1.2G MT. The figure quoted in this article and the greentech media article is a factor of 1000 off.

  • Banned by Bob

    One more benefit of Solar, as peak power demand in the US typically occurs late on summer afternoons. Peak shaving plus relief on the grid.

    • bink

      Banned, where are you living? solar is ramping down as peak is going up in the Southeast.

      • sault

        Solar output is still 70% of its max by 3pm local time, and this is the heat of the day. While solar and peak demand are not exactly aligned, it does help a great deal. Local storage options will make it an even more valuable energy source.

        • Omega Centauri

          Peak AC demand will be after peak temperature. It takes time for the heat pulse to get through walls, attics and ceilings. Then many places, including California have an evening peak, thats what is meant we we speak of “the duck”.

          I think PV is more than 70% on summer at 3PM (or probably even 5PM), unless you are factoring in cloudy afternoons due to cumulus buildup.

          • RobS

            You can precool some hours before peak temperature and the cooler thermal mass in the interior will then oppose the heat pulse you speak off. This can easily be achieved in a centrally directed way to provide demand response services to significantly reduce peak demand. The other strategy is west facing panels which peak at or even just after peak demand, compared with South facing panels (or north in the Southern Hemisphere) which peak 3-4 hours earlier. Finally it is highly likely in the next 3-5 years we will see small storage buffers of ~3-4 hours of stored demand being developed at cost effective prices which will enable time shifting of peak demand and peak supply.

          • Omega Centauri

            Yes you could precool. But getting enough people to acually doit is the issue. Maybe a combination of TOU rates and smart thromstats will do the trick?

            At least in California the duck’s beak peak is around 9PM, PV starts really cutting off after about 7, so you still need some way to shift demand/supply. Altering thermostat values as you suggest would substitute cheal thermal storage for pricier batteries (or grid based storage of another type).

          • RobS

            I don’t expect many people to do it manually I expect smart systems will do it automatically. The system I envision is along the lines of the utility having minute to minute control over your AC, with a contract to keep your home temperature in a certain range, the option to take back control at any particular time for a fee (say a $3 penalty for each 24 hour period where you take manual control) and in return they offer you a 5% discount on your utility bill.

          • Omega Centauri

            In California half or more of AC demand could be met by precooling with nighttime air, yet I’d wager less than 2% of people take advantage of this. Would the utility feel motivated here, the demand is cut from the early part of the day and would have no effect of the largest load of the season. Also day to day load would be more variable.

          • Bob_Wallace

            Ice/cold water/salts storage for AC. Use a heat pump.

            Simple solution. Store up midday solar or late night wind. Whichever’s cheapest.

          • Bob_Wallace

            I’m starting to get a big smile on my face when people talk about the duck.
            Just shortly back we were talking about whether solar would work/ever get installed. Now we’re realizing it will and that it will knock the heck out of the midday peak, leaving the old ‘later hours’ peak intact.

            Now people are acting as if solar is evil or something because it’s not dealing with post Sun demand.

            Storage or import wind from someplace. Shift some load. The duck’s head is simply a problem to be addressed. Celebrate creating the belly.

          • Omega Centauri

            It is true, my attitude has changed. It used to be about a glass a quarter full, now the glass is half empty, and filling the other half seems urgent.

        • Bob_Wallace

          Point some west.

          Extend the solar day.

          • Ronald Brakels

            Yes, we get that too in Australia, whingers are now complaining that solar is no good because it doesn’t produce enough electricity. Give it some time, it’s getting there! And it’s chewing up coal and even gas plants on the way and spitting out mothballs. (About 10% of Australia’s coal capacity is in moth balls – not sure if that includes brown coal, but a filthy brown coal plant recently shut down so maybe it does.)

          • Ronald Brakels

            Australia’s got existing transmission capacity heading west into the interior from the inhabited east coast. Seems to me they could all be used to send solar power back east when the sun has set on the coast. If we get utility scale solar that’s going to be a logical place to put it.

          • Bob_Wallace

            Sounds like a business opportunity. Might spread that idea around to various people in the solar industry and see if it takes hold.

            A coast to coast UHVDC line could give you a very long solar day. 4,000 km/2,400 miles. Not out of question.

            How long would a east-coast-facing-east and west-coast-facing-west solar-system day be? Half the clock?

          • Ronald Brakels

            Well, there’s very close to two and a half hours difference between sunrise on furthest sides of the country so there would be daylight somwhere in Australia for an average of about 17 hours a day. But it costs maybe $8 billion to build 1 gigawatt of HVDC cable across Australia. At $500 for a kilowatt-hour of storage and the solar PV to charge it we could use the same money to buy enough storage and PV to provide a gigawatt of power for 16 hours, so coast to coast cable doesn’t beat storage.

          • Omega Centauri

            Go with utility scale on trackers, then you extend both morning and evening production. Storage ought to be easier to manage on that scale too. As much as we love distributed generation the heavy lifting is going to be done by utility scale.

          • Bob_Wallace

            Panels are likely to get so cheap that tracking won’t pay for itself. Cheaper to give away the 20% loss with E/W facing panels.

            Tracking hardware costs. And racks of panels take up more space in order to avoid shadowing. Plus tracking introduces more maintenance costs.

            If we look at Germany and Australia the heavy lifting is done by houses.

          • Omega Centauri

            I was responding to a point panels west comment. There are of course different measures of goodness for a residential user, a utility scale provider, and the grid operator. The first two want to maximize savings or profits, the last one worries about system stability implications. I think residential DG is going to saturate the suppy of available rooftops (including willing residents) wel below 100% penetration. Adding utility scale on trackers is one way to fill in the gap.

          • Bob_Wallace

            “I think residential DG is going to saturate the suppy of available rooftops (including willing residents) wel below 100% penetration.”

            Each (appropriately sized) rooftop system produces 4x to 5+x as much electricity as that house uses while the Sun is shining. If you live in a 4.5 avg solar hour area and produce what you use in a year then you have to produce, on average, (24/4.5)x or 5.3x as much when your panels are cooking.
            If we get panels on 25% of all roofs we probably have all the solar we can use. (Assuming none is stored.)

            And solar systems take up only part of a roof slope for the average house.

          • Omega Centauri

            What sort of rates do you think the utility is going to give to homeowners who produce three or four times what they consume? I can’t see them offering retail type rates, especially because the juice will come when due to lots of solar its value is low. A rooftop won’t come close to competing with a utility scale farm. We also need to power other sectors, not just residences. And with any luck this will include transportation.

          • Bob_Wallace

            I don’t think utilities should be required to purchase at retail. They need some sort of a price break in order to stay in business.

            There would likely need to be some sort of rate setting mechanism/agency that was responsible for finding a rate fair to both sides.

  • JamesWimberley

    It’s not the topic of the post, but I wish Roy had used some photos of modern pylons that aren’t eyesores. The best – and most expensive – is France’s Roseau. Gallery in an old blog post of mine.
    http://www.samefacts.com/wp-content/uploads/2011/05/photo_pylones.jpg

    • Ronald Brakels

      I can only see ten triangles on the pole on the left in your picture, James, while in Roy’s picture I could count triangles all day long. So I’ve got to say Roy’s is far superior asthetically and I’m sure Pythagoras and almost anyone who enjoys a good hard Picasso would agree.

  • Ronald Brakels

    Pruning remote areas off the grid through the use of solar PV and energy storage as is being done in Queensland and Western Australia is also another way to reduce grid losses, but even though those electricity links are quite lossy, remote areas use such a small portion of total electricity generation it probably won’t make a much of a difference to the overall loss figures.

    • RobS

      It’s all about the cost and technology creep though. In the initial stages replacing transmitted energy with storage will be cost effective when your transmission lines exceed 500 miles, then 450, then 400 etc etc etc until eventually in ~10-20 years it will be cost effective when your transmission line exceeds 0.01 mile ie the centre of cities. We saw the same evolution occur with solar panels where initially they were only cost effective on satellites, then remote cabins and telecommunications infrastructure, then regional areas and now in the cities, the economics of storage will occur in a similar phased way.

      • Ronald Brakels

        That’s some pretty cheap and efficient solar and some incredibly cheap storage that will be needed to make it not worthwhile to not maintain a local grid. It’s also likely to require significant improvements in efficiency. My guess is towns and cities will still be using their existing grids in 20 years time, although they have been pared back to save on maintenance costs, and exisiting long distance transmission will still be used, although there may be places where that will be pared back too. After all, right now in Australia we got a subsation or two that has never been used and may never be used. And the Stuart Mountain 440 megawatt kerosene plant? Do they ever even turn that on anymore? Might be time to ship it to Africa along with its transmission lines.

        • Ronald Brakels

          A little trivia: Ergon Energy, a Queensland electricity utility company in Australia, has about one customer for every 230 meters of transmission infrastructure. They are looking to improve that ratio. Each customer gets subsidised about $900 a year to pay for it.

  • Russell

    “That’s around 1.2 trillion metric tons of CO2 dumped into the atmosphere.” 1.2 trillion tons extra per year – Really? isn’t that more than the entire amount mankind puts into the atmosphere in one year, looks like a unit error there somewhere. It has been questioned on GTM also I see.

    • M_Rab

      That would be ~1.2 billion tons. A kWh produces about 0.9kg CO2, not a ton!

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