Clean & Clean-burn: Renewable Energy & Natural Gas powered Electricity Grids

by John Brian Shannon

Clean and Clean-Burn: Energy, the way it should be

Planetary energy graphic courtesy of Perez and Perez.
Planetary energy graphic courtesy of Perez and Perez.

Of all the energy that is available to us, solar energy is by far the most available and the most evenly distributed energy resource on planet Earth.

Wind and Solar + natural gas = Synergy

  • Solar is available all day every day. But not at night.
  • Wind is available day and night, but it can produce variable power levels as the wind blows over the landscape.
  • Meanwhile, offshore wind turbines produce constant power, spinning at constant speeds for years at a time — except when an operator locks the blades during large storms or during the annual maintenance inspection.

Both solar power and wind power face varying levels of ‘intermittency‘ — which requires the use of ‘peaking power plants‘ or ‘load-following’ power plants — to meet total demand.

‘Catch my Fall’ — All electrical power generators are interdependent

How electricity grids use different power generators to meet total and constantly changing electricity demand.

In the case of renewable energy, the negatives include some variability in the total output of solar power or wind power generation due to temporary cloud cover or storms. At such times, natural gas-fired generation can ramp-up to cover any shortfall.

Note: This is a common and daily energy grid practice whether renewable energy is involved or not. Some gas-fired power plants are called peaking power plants which quickly ramp-up to meet output shortfalls. In fact, peaking power plants (which are almost always gas-fired) were created to meet temporary shortfalls — and were in widespread use long before renewable energy ever hit the market.

Also in the case of renewable energy, another negative is that the Sun disappears at night and solar panels stop contributing to the grid. And unless you have offshore wind turbines to make up the shortfall, onshore wind turbines may fall short of total demand. So at night, you need reliable power to make up shortfalls in primary generation.

Note: This is a common and daily energy grid practice whether renewable energy is involved or not. To cover this situation load-following power plants were designed to meet larger output shortfalls. In fact, load-following power plants were created to meet larger, daily, shortfalls — and were in widespread use long before renewable energy ever hit the market.

In the case of natural gas, the negative is that gas is subject to wild price swings, thereby making gas-fired generation very expensive. Which is why it evolved into peaking power plants, less often in the load-following role and almost never as a baseload power generator.

The other negative associated with natural gas is of course, the fact that gas turbines put out plenty of CO2. That we can deal with. Unlike coal, where the CO2 portion of the airborne emissions are almost the least of our worries — as coal emissions are loaded with toxic heavy metals, soot and other airborne toxins.

How can we deal with the CO2 emitted by gas-fired power plants?

As gas-fired peaking power plants typically fire up anywhere from a couple of dozen hours annually, to a few hours of every day (usually to cover the additional load of many air conditioners suddenly switching on during hot summer days, for example) we aren’t talking about a whole lot of CO2.

Gas-fired load-following power plants typically run for a few hours every day and to cover demand in case of primary generator (like hydro-electric or nuclear power plant) maintenance. In the case of load-following plants, much more CO2 is produced annually.

Carbon Capture and Sequestration (CCS) of gas-fired CO2 emissions via tree planting

  • Peaking power plants operate for a few hours per year. We’re not talking that much CO2.
  • Load-following power plants operate for many hours per year. More CO2.

But still, each mature tree absorbs (a low average of) 1 ton of CO2 from the atmosphere and keeps it in storage for many decades. Some trees, like the ancient Sequoia trees in California, are 3700 years old and store 26 tons of CO2 each! Certain trees native to Australia store even more carbon and live longer than Sequoia trees.

And, as anyone who has worked in the forest industry knows; Once that first planting hits maturity (in about 10 years) they will begin dropping their yearly seeds. Some trees like the cottonwood tree produce 1 million seeds annually for the life of the tree. American Elm trees set 5 million seeds per year. More trees. Always good.

It’s an easy calculation: “How many tons of CO2 did ‘ABC’ gas-fired power plant output last year?”
Therefore: “How many trees do we need to plant, in order to cover those emissions?”

Simply plant a corresponding number of trees and presto! gas-fired generation is carbon neutral

By calculating how many tons each gas-fired peaking power plant contributes and planting enough trees each year to cover their CO2 contribution, tree planting could allow gas-fired power plants to become as carbon neutral as solar power or wind power.

The total number of trees that we would need to plant in order to draw gas-fired peaking power plant CO2 emissions down to zero would be a relatively small number, per local power plant.

By calculating how many tons each gas-fired load-following power plant contributes and planting enough trees annually to cover their CO2 contribution they too could become just as carbon neutral as solar panels or wind turbines. Many more trees, but still doable and a simple solution!

The total number of trees that we would need to plant in order to draw gas-fired load-following power plant CO2 emissions down to zero would be a much larger number. But not an impossible number.

So now is the time to get kids involved as part of their scholastic environmental studies, planting trees one day per month for the entire school year.

Let the gas-fired power plant operators contribute the tree seedlings as part of their media message that the local gas-fired power plant is completely carbon neutral (ta-da!) due to the combined forces of the power plant operator, the natural carbon storage attributes of trees, and students.

Up to one million trees could be planted annually if every school (all grades) in North America contributed to the effort — thereby sequestering an amount of CO2 equal to, or greater than, all gas-fired generation on the continent.

It’s so simple when you want something to work. Hallelujah!

Baseload, peaking, and load-following power plants

Historically, natural gas was too expensive to used in baseload power plants due to the wildly fluctuating natural gas pricing and high distribution costs, but it is in wide use around the world in the peaking power plant role, and less often, in the load following power plant role.

Renewable energy power plants can be linked to ‘peaking’ or ‘load-following’ natural gas-fired power plants to assure uninterrupted power flows.

Peaking power plants operate only during times of peak demand.

In countries with widespread air conditioning, demand peaks around the middle of the afternoon, so a typical peaking power plant may start up a couple of hours before this point and shut down a couple of hours after.

However, the duration of operation for peaking plants varies from a good portion of every day to a couple dozen hours per year.

Peaking power plants include hydroelectric and gas turbine power plants. Many gas turbine power plants can be fueled with natural gas or diesel. — Wikipedia

Using natural gas for baseload power

Natural gas has some strong points in its favour. Often it is the case that we can tap into existing underground gas reservoirs by simply drilling a pipe into naturally occurring caverns in the Earth which have filled with natural gas over many millions of years. In such cases, all that is required is some minor processing to remove impurities and adding some moisture and CO2 to enable safe transport (whether by pipeline, railway, or truck) to gas-fired power plants which may be located hundreds of miles away.

It is the natural gas market pricing system that prevents gas from becoming anything other than a stopgap energy generator (read: peaking or load-following) and almost never a baseload energy generator.

Let’s look at local solutions to that problem.

Waste-to-Fuels

Several corporations are working with local governments to find innovative ways to capture landfill methane gas to produce electricity from it.

Keep in mind that the methane gas that escapes from every single landfill in the world (whether still operating or having ceased operations long ago) is 23 times more damaging to the atmosphere than CO2.

Increasingly, landfills are now installing perforated pipes underground which draw the landfill gas (so-called ‘swamp methane’) to an on-site processing facility. It is a low-grade gas which is sometimes blended with conventional natural gas to create an effective transportation or power generation fuel. Visit the Caterpillar Gas Power Solutions website here.

Waste Management is a global leader in the implementation of this technology, using its own landfills and municipal landfills across North America to produce over 550 megawatts of electricity, which is enough to power more than 440,000 homes. This amount of energy is equivalent to offsetting over 2.2 million tons of coal per year. Many more similar operations are under construction as you read this. Read the Waste Management landfill bioreactor brochure (downloadable PDF) here.

Durban, South Africa, a city of 3.5 million people, has created a huge Waste-to-Fuel landfill power plant that provides electricity to more than 5000 nearby homes.

Durban Solid Waste receives 4000 tons of trash each weekday which produces some 2600 cubic metres of gas every day of the year.

The GE Clean Cycle Waste-to-Fuel power plant arrives in 4 large shipping containers, and once connected to the gas supply pipeline it is ready to power nearby buildings and to sell surplus power to the grid.

One GE Clean Cycle Waste-to-Fuel power plant unit can generate 1 million kWh per year from waste heat and avoid more than 350 metric tons of CO2 per year, equivalent to the emissions of almost 200 cars.

Blending Conventional Natural Gas with Landfill Gas

As conventional natural gas is expensive (and much of the cost is associated with transportation of the gas over long distances) when we blend it 50/50 with landfill gas, we drop the cost of the gas by half. Thereby making blended natural gas (from two very different sources) more competitive as a power generation fuel.

By blending conventional natural gas 50/50 with landfill gas; We could produce baseload power with it — but more likely than that, we could use it to produce reasonably-priced load-following or peaking power to augment existing and future renewable energy power plants — rather than allow all that raw methane from landfills to escape into the atmosphere.

Best of Both Worlds — Renewable Energy and Natural Gas

Partnering renewable energy with natural gas in this way allows each type of power generator to work to their best strength — while countering negatives associated with either renewable energy or natural gas.

Renewable power generation and lower cost natural gas can work together to make coal-fired electrical power generation obsolete and accelerate progress toward our clean air goals.

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Creating Jobs via Renewable Energy Adoption

Creating Jobs via Renewable Energy Adoption | 07/02/15
by John Brian Shannon John Brian Shannon

Adding new jobs to the economy is always a good thing

In good times or bad, adding more jobs to the economy always equates to higher GDP, lower debt-to-GDP levels, lower unemployment insurance expenditures and higher revenues for governments from income tax and sales tax.

There are no examples where adding net jobs to an economy has resulted in a net loss to the economy

It’s positive for individuals too. Higher employment levels generally lead to higher incomes, small and large businesses notice increased revenue and there is always the chance that companies may begin to expand their facilities and hire more staff to handle increased sales.

Which is why the case to add more renewable energy is so compelling

IRENA Renewable Energy jobs infographic - Global
Global jobs created by the Renewable Energy industry. Image courtesy of IRENA.

Over decades of time, mature industries have figured out ways to increase output with fewer employees.

In the Top 10 on the mature industry list, must certainly be hydro-electric power plants, followed by nuclear power plants and gas-fired power plants. There we have astronomical installation costs and employment numbers — but once construction of the power plant is completed only very low staffing levels remain to operate the power plant.

Which is very unlike the case with renewable energy. Why? Because once a multi-billion dollar hydro-electric dam is built, it’s built. You don’t need to build thousands of them per day.

It’s the same with multi-billion dollar nuclear power plants — all you need after the construction phase ends are a small number of highly trained people to monitor the various systems. And some security people. That’s it.

With solar panels, a factory must produce 1000 per day (or more, in the case of larger factories) every weekday. Suitable markets must be found, factories must be built/leased, production floors must be built, materials sourced, and the panels themselves must be designed and engineered, assembled, packed, shipped and accounted for. Accountants do what they must do, marketing people manage a steady train of media events, trade shows and advertising programs, and on and on it goes — and all of it is a part of the solar industry. That activity creates work for thousands of people, every workday of the year. (And that short description doesn’t begin to cover it)

Then there are the solar panel installers, the sales teams/estimators, and the companies that build the inverter systems, which is a whole other value chain.

The wind power industry can also make high employment/lower power plant cost claims — although wind turbines average about $1 million dollars each — as opposed to solar panels which mostly range from $10 each to $400 each, depending on their size and composition.

Renewable energy is hugely labour-intensive and many thousands of permanent jobs are created — quite the opposite of conventional power generation

It is worth commenting that 2014 renewable energy employment numbers (once they become available) will show a significant improvement over 2013 numbers.

The entire industry is surging forward unequally, but renewable energy growth in some nations is trending upwards like the Millennium Falcon trends upwards.

Below is a breakdown graphic showing the labour intensity of the various types of renewable energy.

Globally, 6.5 million jobs were created in 2013 from renewable energy.
Globally, 6.5 million jobs were created in 2013 from renewable energy. Image courtesy of IRENA.

We can also look at a breakdown graphic of jobs per MW of electricity produced where we see that coal, nuclear, and oil & gas require very few humans per MW.

Potential jobs by MegaWatt (MW) by energy type. Image courtesy of IRENA.
Potential jobs by MegaWatt (MW) by energy type. Image courtesy of IRENA.

There’s no doubt that global energy demand is growing, not only in the developed world, but in the developing world as well.

Each kind of energy (non-renewable and renewable energy) has it’s own pros and cons.

One of them, is that non-renewable energy requires far fewer humans over the lifetime of the power plant.

Renewable energy on the other hand, is a rapidly-growing manufacturing, installation, and marketing industry that requires evermore blue collar and white collar employees.

And now that solar power, wind power, and biomass power have reached — or are within months of matching (per kWh) price parity with non-renewable power plants — the question becomes;

Do we want to employ 1.3 persons full-time per MW, or do we want to employ up to 24 people full-time per MW?

For comparison purposes, the typical coal, gas, or nuclear power plant can supply 1000 MW (or 1 GigaWatt) of electrical generation capacity, while the average wind turbine can supply 1 MW each.

The average 1 MW wind turbine costs about $1 million apiece, so to get 1 GW of electrical generation capacity, you need to install 1000 of them (1000 x $1 million each = $1 billion total) and the installation and connection to the grid of that many turbines might take up to 24 months.

Each 1 GW installation of coal, gas, or nuclear power, costs well over $1 billion and can take up to 15 years to construction completion.

For example, the 2.4 GW nuclear power plant under construction in Vogtle, Georgia was originally planned to cost $14 billion, but due to construction and regulatory delays (and now lawsuits between the principals involved) it may cost significantly more than that and the completion date has been extended by months, or even years.

At this point, the total cost may exceed $17 billion and it may take an extra year to complete — for a total of 2.4 GW of installed capacity over 11 years of construction and delays, at a total cost of $7.08 billion per GigaWatt. It won’t get any better than that, but it may get much worse.

The 10-year construction plan is already behind schedule by 14-months, and now faces an additional (up to) 18-month delay.

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One point about Plant Vogtle (the official name of the plant) is that the two 1200 MW (1.2 GW) reactors are of the latest GE/Toshiba AP-1000 design, noted for their passive safety systems and additional safety redundancies built into the power plant. If you’re going to build a nuclear power plant it might as well be the safest one.

As new capacity is added to global electrical grids, more of it is renewable energy

More utility companies are adding new renewable energy capacity as opposed to adding new non-renewable energy capacity due to faster installation time frames, fewer regulatory delays, the lack of fuel supply concerns going forward, and total installation cost per GigaWatt.

In 2013, of the 207 GW added to the world’s electrical grids — renewable energy accounted for 120 GW of new installations, while 87 GW accounted for non-renewable energy.

Once the 2014 numbers are released to the public, the renewable energy statistic will have improved over 2013’s numbers. And 2016 should easily surpass the 70/30 metric.

It’s easy to visualize this in the chart below.

Global generation capacity additions to 2013 - renewables vs. non-renewables. Image courtesy of IRENA.
Global generation capacity additions – renewables vs. non-renewables. Image courtesy of IRENA.

As renewable energy displaces non-renewable energy additions to the grid — remember that renewable energy gets only 1/4 of the subsidies that fossil fuel energy gets!

See: Energy Subsidies: The Case for a Level Playing Field

Imagine if renewable power generation got the same subsidies as non-renewable energy power generation

In practical terms, it would mean that 100% of all new power generation would be renewable energy.

Also, the renewable energy manufacturing sector would need to accelerate production to meet demand — meaning many hundreds of thousands of permanent jobs would be created immediately after the levelized subsidy was announced.

Between 2017-2019 — and even with the higher subsidies enjoyed by coal, nuclear, and oil & gas — it will cost less to install new renewable energy power plants than to install new non-renewable energy power plants.

Germany is one of the countries leading the transition to renewable energy

Due to German public pressure in the aftermath of the Fukushima-Daiichi incident in March 2011, Germany shut down nearly half of their nuclear power plants and were forced to accelerate their transition timeline to renewable energy.

This unexpected development created additional costs for Germany, but regardless, their Energiewende program is still a stunning renewable energy success story.

Although progress has slowed from the frenetic pace of 2011-2013, Germany is very much a world leader in the transition to renewable energy.

Renewable energies were the number 1 source of power production for the first time ever. [In Germany]

Renewables gained slightly in 2014 and now comprise 27.3 percent of domestic power consumption.

They have now permanently displaced lignite [brown coal] as the top source of power in the electricity mix. — The Energiewende in the Power Sector : State of Affairs 2014 (downloadable PDF)

Here is a nice chart, courtesy of our friends at the Fraunhofer Institute in Germany.

How goes the Energiewende, Germany? Es geht gut! Image courtesy of the Fraunhofer Institute.
How goes the Energiewende, Germany? Es geht gut! Image courtesy of the Fraunhofer Institute.

There is no doubt that the world will transition to renewable energy, and even major oil companies like Shell and BP are in agreement that by the year 2100, almost 95% of all energy demand will be met by renewable energy.

In one scenario, Shell says that by 2060 the largest energy provider will be solar power.

How quickly that energy transition will occur, is what the present conversation is all about

Increasingly, the conversation centres around matching renewable energy subsidies with the (4x higher) subsidies enjoyed by coal, nuclear, and oil & gas power generation.

So get ready to breathe fresh air, because change is coming!

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Thank you to our friends at IRENA and at Fraunhofer Institute for their valuable graphics!