Efficiency and Conservation – Nurturing The Negawatt

An Introduction

HVDC Transmission

LED Lighting

The Power-Pipe


Toronto’s Deep Lake Water Cooling

The Internal Combustion Engine

Potential and Pitfalls

An Introduction

“Turn out the lights!” That was a constant refrain in my childhood home, heard whenever I wandered from one room to another. My mother, who grew up in the UK during the Second World War, saw conservation of any kind as a virtue: turning down the thermostat in winter, carpooling and, yes, flicking out the lights when you leave the room. Conservation means going without or changing your behavior to make do with less. So far, though, the world has shown that it’s unwilling to give up anything in order to kick our fossil fuel habit.

If conservation means doing without, efficiency means doing something smarter, with the same result. A house is more efficient when it’s insulated, because it holds in heat. A diesel engine is more efficient than gasoline, because it wastes less energy on heat and light. Efficiency is like an athlete – think of Olympic runner Usain Bolt, whose easy stride avoids unnecessary and ungainly movements. That’s efficiency: energy used gracefully, focused on a single purpose.

And it works. You’ve heard of the megawatt, but have you heard of the negawatt? That’s the term coined by energy expert Amory Lovins to describe the power of my mother’s flipped switch or the grace of an efficient process. Not using a watt of energy is the same as producing one, but cheaper and easier. They may not be as sexy as a shiny new power plant, but negawatts have nevertheless been the single largest’ contributor to the US energy sector since 1975 – bigger than nuclear, coal or oil. Persian Gulf oil has contributed less than 10% the energy delivered by negawatts since the OPEC crisis.

Still have your doubts about the power of the negawatt? Harken back to the year 2000, when California faced rolling brownouts. The state was in a panic, and then-Vice-President (and fan of coal) Dick Cheney declared the need to build a power plant every week to deal with the problem.2 The White House announced that more than 1,000 new power plants were required nationwide. “Pump up the supply!” was the cry.

Quietly and quickly, however, Californians lowered their energy use rather than face more brownouts. One third of them cut usage by 20%. Within the first six months of 2001, Californians had lowered their consumption by the equivalent of 1 0 power plants. They produced negawatts faster than new plants could put out megawatts – and developers put their plans for new plants back on the shelves.

When Jimmy Carter reacted to the OPEC crisis of 1979 by initiating new rules3 for automotive fuel efficiency, Americans churned out negawatts so fast, they changed the face of global oil production. In less than a decade, the oil market shrank by 10%.

Negawatts require conservation and efficiency. Together, they are the cheapest, 4 fastest and biggest new source of energy available.

If conservation means changing our behavior, we’ll need a strong price signal to make it happen. Until we pay more for power, we’ll continue to cool our movie theaters so much that half the crowd wears sweaters, and our office buildings so much that people put electric heaters under their desks. My mother is not typical – most of us will not turn out the lights until we have to.

This book celebrates technology, and that’s what drives efficiency – new, more graceful ways of using energy, performing tasks without waste, and reducing energy without sacrifice. We’ve already seen some examples: geo-exchange heating and cooling, mass transit, smart buildings. Here are a couple more: planting shade trees that can reduce indoor cooling requirements by almost 5O%, and painting flat roofs white to reflect heat. There are thousands of others.

What follows is just a taste.

HVDC Transmission

In the late 1800s, two great energy pioneers fought a battle over how to move electricity. On one side was Nicola Tesla, champion of alternating current (AC), where power swings constantly from positive to negative voltage. On the other side, Thomas Edison was fighting for a constant, direct current (DC). Tesla won the day, and for good reason. Over short distances, AC is more efficient. But more than 100 years later, Edison may finally have his way, at least for cross-country transmission.

Sending power over long distances especially using AC – means losing some of that power to resistance. Transmission losses total about 7%, but that’s mainly over short distances – from power plants to the cities and homes they feed. If we’re trying to send power farther, like solar from the American southwest to New York, those losses get much higher.

That’s where high voltage5 direct current (HVDC) comes in. Sending power over DC lines results in less loss due to resistance than using AC, and there’s a critical distance7 at which DC beats AC – for anything over a few hundred miles, DC wins. For the thousands of miles required for cross-country transmission, it wins hands down. You can also send more power over a single, thinner8 cable with HVDC, reducing the amount of money required to install it in the first place.

International powerhouse ABB is emerging as the leader in HVDC technology. The Swiss company is currently building the longest and biggest HVDC transmission line ever, in China. It will carry 6,400 megawatts of power over more than 1,240 miles (2,000 kilometres). ABB has also built the longest underwater HVDC cable, a 360-mile (580- kilometre) connection between Norway and the Netherlands.

LED Lighting

We took a look at my own project, the Planet Traveler Hotel, in Geothermal section. Since our goal is to build North America’s lowest-carbon hotel, you’d think the last thing we’d do is light the whole place up at night. But we’re using LED lighting, the most efficient lighting around.

Using one-tenth the energy of an incandescent bulb to produce the same amount of light, LEDs can last more than 50 times longer. The technology is so efficient, we can light up the entire hotel, inside and out, for the same amount of energy as it takes to run a two-slice toaster.

Using a regular incandescent or halogen bulb is akin to building a campfire for light – the light is just a by-product of heating up the filament until it’s white-hot. LEDs (and their close competitor, the compact florescent bulb) are just the opposite: The energy they use goes directly to making light.

How do they work? LEDs are like computer chips: A semiconductor is injected with impurities, or “holes,” which are atoms missing an electron. When a passing electron falls into a hole, it releases a photon, or light. Almost all the energy used to move the electrons gets emitted as light, not heat.

The pitfall is that LED lighting is expensive. Our lights will eventually pay for themselves, but not for many years. It’s also a new and growing industry, so the leaders haven’t emerged just yet.

The Power-Pipe

As someone who loves a long, steamy shower, I’ve watched a lot of hot water go down the drain. I can use some solar thermal to fill the hot water tank, but I’m still heating up the sewer as much as my shower. A small company based in Waterloo, Canada, has a simple solution: Replace your drain with a Power-Pipe and send all that heat right back to your hot water tank.

How does it work? The Power-Pipe is a long, copper drainpipe wrapped in copper tubing. As gravity-driven water swirls down the drain, it clings to the sides of the pipe (the same principle as the swirling water in a flushing toilet). Meanwhile, water heading for the hot water tank-to replace what the shower is using – is running through the copper tubing. Copper transfers heat, so that incoming water is preheated by the stuff going down the drain. It’s called “drain water heat recapture,” and it couldn’t be simpler.

Home showers are just the start. The real potential is in industrial processes that require lots of heat, like food preparation, pulp and paper, and brewing. Power-Pipes can grab nearly two-thirds of the heat going down the drain. There is a pitfall: The drainpipes in existing buildings are typically hidden behind walls or under floors. The added hassle and cost of renovations makes the technology a harder sell.


Most of the energy in a power plant gets spewed out the chimney as waste heat, just like the exhaust of your car. It’s a by-product, thrown out like trash. We’re making electricity and heating the sky. We can do better than that, by using that waste heat to power buildings or to make more electricity. Cogeneration – also known as combined heat and power (CHP) – can raise the efficiency of a power plant from one-third to nearly 90%.

The easiest way is called “district heating” – pouring all that waste heat into nearby buildings. In New York City, more than 100,000 buildings are heated with steam from seven local cogeneration plants. Cogeneration plants exist all over Europe, with Denmark leading the way. The nation gets more than half of its energy from waste heat. It’s not just hot air, either. During the summer months, heat can be fed into “absorption chillers” – big refrigerators that run on heat to cool buildings. A tri-cycle plant adds an extra step: The exhaust heat is first used to create steam and generate more electricity, while the final exhaust goes to district heating and cooling. Double-dipping on waste heat.

It sounds easy, and it is. There’s a problem, though: The power plants need to be close to the buildings they heat, but most of our electrical production takes place far from urban centers. That’s why most cogeneration plants are small and scaled to power office buildings, a condo tower or one local neighborhood. Then there’s the WhipserGen, a Stirling9 engine that runs quietly in your basement, providing heat and power for a single home. It’s a furnace, boiler and electrical utility all in one.

The potential? In Germany, half 10 of all electrical production could come from cogeneration, and there’s no reason to think other countries couldn’t do the same. British writer George Monbiot points out that the amount of heat wasted by UK power plants is roughly equal to the energy that’s used for household heating.11

Toronto’s Deep Lake Water Cooling

Toronto sits on the shore of one of the world’s largest and deepest lakes. Having swum in Lake Ontario many times, I can attest that even the surface is cold – even at the height of summer! Water at the bottom of the lake remains a constant 39 F (4 C) year-round. Meanwhile, as the sun shines on the glass walled office towers that dominate Toronto’s downtown skyline, huge air conditioners roar to life, working to keep them cool. Hmm … loud, energy-sucking air conditioners running alongside a huge body of cold water that stretches as far as the eye can see. There must be a better way.

There is. In 2004, Toronto’s Enwave Energy turned on the Deep Lake Water Cooling system. The idea is simple: Use the cold water of Lake Ontario to replace the air conditioning needs of the downtown core.

It’s like the district heating and cooling systems we’ve just seen, but using lake water as a source of cool air.

How does it work? Remember geo-exchange from previous pages? It’s much the same. Enwave pumps 4 C water from 280 feet (85 metres) deep and three miles (five kilometres) out, passing it through heat-exchangers before sending it to Toronto’s water system. That cools a chilled-water closed loop, which runs through the downtown core. Buildings reject heat into that loop using their own heat-exchangers.

It works beautifully, saving an estimated 60 megawatts on a hot summer’s day. That’s enough to power 60,000 homes. Some critics worry that Enwave is injecting the lake with unnaturally warm water, but the company takes in only enough to fill Toronto’s water needs, so it’s not having a major impact on the lake.

The Internal Cumbustion Engine

President Carter’s Corporate Average Fuel Efficiency standards may have increased the overall fuel efficiency of America’s fleet by 20%, but we lost those gains with loopholes big enough to drive an SUV through. By 2003, the efficiency of the Ford fleet was no better than it was during the time of the Model T, and the SUV was America’s champion. Not the wisest move. Inefficiency was part of what brought the once-great American car companies to their knees in 2009.

How efficient could we make cars? In Europe, even the troubled US automakers are way ahead. DaimlerChrysler and General Motors each produce family sedans that get close to 80 miles per gallon (three litres per 100 kilometres). Volkswagen sells a four-seater that gets about the same, and it has also premiered an ultralight diesel that gets almost 300 miles per gallon (less than one litre per 100 kilometres). In comparison, a Hummer gets 10 miles per gallon, and the US average is around 20. Disgraceful.

President Obama has seen the light. His new fuel-efficiency standards will drop American oil consumption by 1.8 billion barrels annually. That’s more than US imports from Saudi Arabia, Libya and Venezuela combined. The bottom line? The American Academy of Sciences stated in 2001 that cost-effective efficiency gains could double the average efficiency of US vehicles, without sacrificing performance or safety.

Double the mileage for the same amount of gas. That’s like comparing Usain Bolt to George Costanza on the 100-metre dash. Who would you rather watch?

Potential and Pitfalls

Negawatts are not just for the virtuous. Underrated and overlooked by an energy industry obsessed with production, they’re the largest source of energy – and the cheapest, too. According to energy experts Amory and Hunter Lovins, it’s possible to reduce energy used by developed countries by at least half, for two cents per saved kilowatt hour. Negawatts will really take off when the Energy Internet lets utilities participate (see Energy Internet page). Total potential?  Half our energy use worldwide.

But here’s the irony: Negawatts are so effective, they can be their own worst enemy. Efficiency and conservation often reduce energy demand so quickly and steeply that the price of power comes crashing down. And when that happens, people stop making negawatts. We’ve seen it happen four times since the 1973 OPEC crisis. Negawatts need to be integrated into a larger strategy.

When Californians ended their energy crisis in 2000 by cutting their power consumption, they didn’t do it out of the goodness of their hearts. They did it because they faced brownouts and spiking energy costs. Conservation may be adopted by some – like my mother – as a virtue in its own right, but for global uptake, we’re going need an ongoing, constant price signal. Efficiencies are driven by the same pricing signal.

There’s some truth to what Dick Cheney said in 2001: “Conservation may be a sign of personal virtue, but it is not a sufficient basis for a sound, comprehensive energy policy.” Cheney’s response was to pump up coal production and other fossil fuels – not exactly the basis of a sound, comprehensive energy policy.12 But a culture of conservation and efficiency does require a price signal to ensure that our self-interest, as well as our virtue, drives us to make negawatts.

The Energy Internet will automate negawatt production, making sure that customers and utilities are paid to produce them. That refrain from my childhood – “Turn out the lights!” will come as an electronic signal straight from the utility. Contrary to what Cheney has said, conservation will become the basis of a sound, comprehensive energy strategy.