A second squeal from the pig

The laws of thermodynamics might be paraphrased as (1) you can’t win, (2) you can’t break even, and (3) you can’t get out of the game. The second law is the frustrating truth that all engineers face. Whenever you change energy from one form to another, you always lose some as heat. Eventually all energy winds up as heat. Some say the universe as a whole will one day end up as one great expanse of uniform heat – the heat death of the universe. A cheerful thought, that.

To an engineer, heat is useless. It is loss. It is the price grudgingly paid for getting work done. The lower the price paid, the greater the success. You might say that the mission of the engineer is to squeeze the very most usable work out of a given unit of fuel before it inevitably becomes worthless, unusable heat.

In this context, the idea of burning fuel for warmth is absurd – all that fuel being turned into heat, with zero work done. And yet we do it all the time. Guelph’s Community Energy Initiative document of 2007 pegged the annual city-wide consumption of natural gas at 231 million cubic metres. Virtually all of that was (and still is) being burned in boilers or furnaces to create heat – heating our buildings, heating our domestic hot water, even heating for cooling (a feat performed by absorption chillers).

There’s another way.

Oink, oink: Conventional methods need 43% more input energy than CHP for the same result

If you burn that fuel in an engine – the same kind of internal combustion engine in your car – you get torque and heat. That torque can turn a generator to produce electricity, while the leftover heat can be used for any of the purposes mentioned above. Using the same fuel to provide both electricity and heat is called Combined Heat and Power, or CHP (also called cogeneration). It gets you a second squeal from the pig. Or, viewed another way (see diagram, from building.co.uk), it gives you 260 units of valuable output from 325 units of fuel; conventional methods require 465 units of fuel (43% more) to produce the same output. If you rely on grid electricity and 80% efficient boilers, CHP is an attractive alternative.

There are variations on the engine idea. Large-scale CHP uses not gas engines but gas turbines – similar to what you find under the wing of a Boeing 737- to produce energy in the range of megawatts rather than kilowatts. At the other end of the scale, there’s a micro-CHP device called BlueGEN that doesn’t burn the fuel at all, but rather runs it through a ceramic fuel cell to convert it to electricity – enough to supply a typical single-family home, with sufficient leftover heat to satisfy the family’s domestic hot water needs.

In areas where the utility grid uses carbon-intensive brown coal for much of its power generation, like the Australian state of Victoria, a product like BlueGEN offers significant savings in carbon emissions compared to grid electricity – a welcome benefit over and above the financial savings. This is partly because coal-fired power plants produce the most carbon of any option on the energy generation menu. It is also because the grid electricity comes with a substantial drag in the form of unusable heat – the coal plants produce steam from high-grade heat, but they can’t use the low-grade heat left over so they discharge it as a waste product. When the fuel is consumed right at the point of use, this waste heat can be put to productive use.

Where the grid has a low carbon intensity, like here in Ontario, one might think that household-scale CHP would be a non-starter. It’s true that the average amount of carbon produced per unit of energy is a lot lower than Down Under in the state of Victoria. However, the average is meaningless in this situation. There are several forms of power generation in the Ontario mix – nuclear for base load, followed by hydroelectric, wind (when it’s available), and finally natural gas. These are dispatched consecutively as demand rises, and shut down in the reverse order as demand drops. As demand falls off, the first source to be shut down is natural gas.

When a household takes itself off the grid by producing its own electricity, that demand comes right off the top of the generation stack. If you’re going to compare the emissions of a product like BlueGEN, you have to compare its emissions against those of the marginal grid generation source – natural gas. During the period from midnight on January 14th, 2015 to 1:00 PM on January 19th, the average emissions factor for the Ontario grid was 73g of CO2 per kilowatt hour (for current data, click here). However, the marginal emissions factor was seven times that figure: 512g CO2/kWh.  By comparison, a BlueGEN unit with waste heat captured for domestic hot water comes in with an emissions factor of 240g CO2/kWh – less than half of the marginal grid emissions intensity.

What would happen if all of Guelph adopted CHP?

Earlier I mentioned that the 2006 city-wide natural gas consumption was 231 million cubic metres. If CHP units (with the efficiencies shown in the diagram) were used to produce the same amount of heat as our furnaces currently do, it would produce 1,402 GWh of electricity. The entire electricity demand of Guelph as of 2006 was 1,630 GWh. So, if we met our heating requirements with CHP units instead of furnaces, we could meet 86% of our city-wide electricity needs at the same time.

We mustn’t forget thermodynamics rule #1 – you can’t win, or rather you can’t get something for nothing. This scenario would double our natural gas consumption. However, even more of that “extra” natural gas – 121 million cubic metres, to be exact – is being burned in a peaker plant anyway to supply our electricity. The reason CHP looks so much better is that peaker plants dissipate their waste heat, rather than getting that all-important second squeal from the pig.

Deployed broadly in Guelph, CHP could save 121 million cubic metres of natural gas per year. That corresponds to 228,000 tonnes of carbon, not to mention $23 million in annual cash savings. It would also mean we produce 86% of our electricity right here within the city limits – a big plus for resiliency in an era when freak ice storms can tear down high voltage transmission lines and leave thousands without power, as happened in Quebec in late 1998.

Let’s get that pig squealing.

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The Big Tent

If energy is the lifeblood of the economy, Guelph – like most communities – is haemorrhaging.

As of 2010, Guelph was spending $500 million per year on energy – electricity and natural gas for buildings and industry, as well as gasoline and diesel fuel for transportation. Where does that money go? A small amount stays in town, to pay for local gas stations, wires and poles, natural gas pipes, and so on. However, that sum is really just rounding error on the total bill. Almost all of the money leaves the city and never comes back. If we take electricity out of the picture, most of what’s left also leaves the province, since local sources of oil and gas are minimal. If the money leaves town, it doesn’t help anyone in town. Energy is a huge drain on the local economy.

If we do nothing, by the time 2031 rolls around, inflation and population growth will have at least doubled the annual spend. A billion dollars will be bleeding out of town every year.

It doesn’t have to be that way. All we need to do is make more, and waste less. We know we can do this, because others have. We can do it without sacrificing comfort and utility. Here in the City of Guelph we have a plan to get there, and we call it our Community Energy Initiative. It has two main parts: Local energy generation, and energy efficiency.

First, we rely almost completely on energy imports. Whether it is electricity coming from Bruce Nuclear or Niagara Falls, natural gas coming from shale deposits in Montana, or oil coming from Fort McMurray bitumen, virtually all the energy we use comes from elsewhere. To pay for it, money leaves our pockets and then leaves town.

However, new technologies mean that we can provide more for ourselves. Combined heat and power technology allows us to use the same fuel – natural gas to start, but eventually locally sourced biomass and biogas – to produce both warmth and electricity. (I like to call this getting a second squeal from the same pig.) Solar energy can also be used to produce both heat and electricity. District energy allows us to take waste heat from industry and supply it to homes, businesses, and other organizations so they don’t have to produce it themselves by burning natural gas.

We already have a combined heat and power plant supplying the West End Community Centre, and two more plants were approved back in April – one at Polycon in the northwest industrial park, the other in the Hanlon Creek Business Park. We have solar thermal panels above the back patio of the Wooly and on top of the River Run Centre and Fire HQ, and, solar photovoltaic panels on top of the Lawn Bowling Club and next to the Speedvale Water Tower. We also have a district energy network growing around the CHP plant in the south end that I already mentioned, and around the Sleeman Centre, which will soon provide heat to the next phase of the Tricar high-rise condo complex at the corner of Wellington and Mcdonnell. This is to say nothing of the DE system that’s been heating the University of Guelph for more than a hundred years. By 2041, half of Guelph’s heating needs will be supplied by district energy.

Second is the matter of energy efficiency. We use far more energy than we need to. If you look at a typical Canadian building through a pair of infrared goggles, it is a kaleidoscope of reds, oranges, and yellows representing embarrassingly large amounts of radiated, wasted energy. A European building will boast a few shades of cool blue. Leading European cities are nearly twice as energy efficient as Guelph is.

Europe hasn’t achieved this through some kind of sorcery, and it’s not as if Europeans are inherently more thrift minded or environmentally friendly. It all comes down to this simple motivating fact: Energy is very expensive in Europe. People, businesses, and other organizations have responded rationally to high energy costs. They have adopted policies, technologies, and behaviours to help them do as much, or more, with less. If we do what they have done, we can achieve what they have achieved.

I’m a fan of Earth Hour and I do my best to participate each year. However, contrary to the message that Earth Hour sends, conservation does not mean freezing in the dark. It just means figuring out ways to reduce how much we waste.

In the near future the City of Guelph will be launching a program called GEERS – Guelph Energy Efficiency Retrofit Services – to help overhaul our existing buildings and stop them from bleeding precious energy.

Earlier I mentioned that Europeans used a combination of policies, technologies, and behaviours to achieve leadership in the energy sector. Policies like the Community Energy Initiative and GEERS, technologies like district energy, and behaviours like participation in Project Neutral will help Guelph to get there too. I encourage everyone to learn more about Project Neutral and how it can help all of us to use less energy, save more of our hard-earned cash, and leave behind a smaller footprint.

It’s an understatement to say that there was an unexpectedly large turnout for the People’s Climate Mobilization on September 21^st of this year. Some of you may have been on the steps of the old Guelph City Hall for the local version of that event. This demonstrated that many people care deeply about climate change. However, “many” is not the same as “all”. For many other people, climate doesn’t matter – or it doesn’t matter as much as jobs, wages, interest rates…in other words, the economy.

Climate is the small tent – rightly or wrongly, not everyone cares about it. The economy is the big tent – everyone gets money somehow, spends money somehow, and has to find a way to somehow make the two numbers match. To make meaningful progress on the climate issue, the conversation must move beyond the environment, and encompass the economy.

Energy is where the environment meets the economy. As a city, we can work together so that by 2031, we will be wasting far less energy, and producing far more of our own, and maybe, just maybe, keeping half a billion dollars right here in Guelph.

That’s a future we can all get excited about.

Postscript: The annual numbers for energy spend (present day and anticipated in 2031) were originally understated by 50%. This has now been corrected.

Energiewende

I spent this week at the penultimate meeting of the Transatlantic Urban Climate Dialogue (TUCD) in Germany, over and over hearing the term energiewende. Some of our hosts translated this as “energy change”, demonstrating characteristic German modesty. If I bought a Tesla Roadster, installed a solar array on the roof of my home to power it, ever after laughing at the price per litre posted at the local petrol station, and then referred to my accomplishment as changing a tire, it would be a similar understatement. Energiewende is no mere change. It is a revolution.

Visible signs of energiewende abound. Solar panels are a common sight on roofs of homes, factories, and institutions – the Free University of Berlin has several hundred kilowatts-worth of photovoltaics atop many buildings erected or annexed during the Cold War era when the city was hemmed in on all sides by the repressive and utterly democracy-free German Democratic Republic. As our train glided across the countryside at 200 kilometres per hour (120 mph) on the way from Berlin to Essen in the Ruhr valley region, we frequently squinted through the rain dotted windows to see farms of wind turbines rising above the landscape, sleek blades silently rotating with elegance and simplicity. From a hilltop in the Ruhr Valley city of Bottrop, a region once synonymous with coal mining, steel production, and air pollution, the silhouettes of massive power plants are visible on the horizon, their gargantuan stacks belching steam and carbon dioxide no longer, mute relics of a largely bygone carbon economy.

Energiewende makes itself felt in other, more subtle ways. Bathroom faucets often have no manual taps, but sensors that only dispense water when you present your hands – no absent-minded soul will ever leave the water running as they exit. Step off the hotel elevator onto your floor, and the hallway almost instantly lights up, activated by motion sensors that ensure all is dark when no one is there to benefit from the light. Step into your hotel room, and you will find all electricity extinguished – until you slip your access card into a slot on the wall by the door. On entering a Canadian hotel room, by contrast, you would find the lights blazing, as they would have been since the cleaner finished up many hours before. (This card slot has an added practical benefit of making sure I never misplace my room key.)

More subtle is the revolutionary way the room is heated. The hotel has no furnace. Hot water is piped into the building from a plant some distance away, a plant which takes waste heat from industry and puts it to work once more. (More on the idea of District Energy, or DE, in my previous post.) Alternatively, in places not yet served by the District Energy network, buildings are served by micro-CHP (Combined Heat and Power) units. As the name suggests, these devices provide both warmth and electricity. DE and CHP are both largely invisible, their components hidden away in basements or buried under pavement.

Finally, and least conspicuous of all, are the elements of the building envelope – energy-efficient windows, insulation, weatherstripping, and air exchange systems – which together help to make European buildings half as energy intensive as their North American counterparts. Our hosts in the city of Bottrop spoke of a number of housing projects which are “net positive”, meaning that the buildings produce more energy than they use. Some such projects are targeted at members of society on the lowest rung of the economic ladder – low-income earners and beneficiaries of social assistance. These people stand to be hardest hit by rising energy prices, and so stand to benefit the most from a dwelling that receives cheques rather than bills from the local utility.

When I think about my home in Ontario, I realize that the province has really missed the boat with its Green Energy Act. So much of the focus is on green energy generation – wind, solar, and biogas. There is an energy conservation component, but it is the poor cousin. The Feed-In Tariff (FIT) program has more than its fair share of flaws, but it stands head and shoulders above the SaveOnEnergy program.

Coal and oil are becoming ever more scarce and hence ever more expensive, and our environment cannot support their continued use. We need to replace all of our dirty energy generation systems with clean ones, make no mistake. This will be a hard hill to climb. But it will be far easier if the hill is shorter. At the same time as a revolution in green energy generation, North America needs a revolution in energy efficiency. District energy systems, combined heat and power, and building envelope improvements are all critical to shrinking the hill.

Our German TUCD hosts often spoke of everything they have yet to accomplish. They haven’t solved every problem – far from it. But they have made incredible progress. They have developed the technologies, the businesses, the public programs, and the social structures to make it happen. Through TUCD, they have been showing us how – we simply needed to ask.

In Germany, I’ve seen the hill. I’ve seen the way the German people are shrinking the hill at the same time as they are climbing it. And I am completely confident that North Americans can follow their lead.

We need our own energiewende. Our German friends are showing us the way.