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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NCCETC Releases Guide to Going Solar in America’s 50 Largest Cities

NCCETC Releases Residential Customer Guide to Going Solar in America’s 50 Largest Cities | 13/01/15
by North Carolina Clean Energy Technology Center

RALEIGH, NC (January 13, 2015) – Today, as part of the U.S. Department of Energy’s SunShot Solar Outreach Partnership (SolarOPs), the N.C. Clean Energy Technology Center (formerly the N.C. Solar Center) announced the release of the second report in its Going Solar in America series:

Going Solar in America: A Guide for Homeowners Considering Solar PV in America’s 50 Largest Cities

The first Going Solar in America report, released last week, ranked America’s 50 largest cities by the financial value rooftop solar offers residential customers. According to the authors’ calculations, a financed solar PV system can be a better investment than the S&P 500 in 46 of the 50 cities.

Going Solar in America report, ranks America’s 50 largest cities by the financial value rooftop solar offers residential customers. Image courtesy of NC Clean Energy Technology Center, N.C. State University.
Going Solar in America report, ranks America’s 50 largest cities by the financial value rooftop solar offers residential customers. Image courtesy of NC Clean Energy Technology Center, N.C. State University.

The second report, released today, provides actionable information to homeowners as a follow-up to these rankings. This customer-facing guide includes descriptions of the policy and incentive options available to homeowners considering solar and information on how to get started. Among topics addressed are solar PV technology, financing options (loans, leases and power purchase agreements), and net metering and “value of solar” tariffs.

Many Americans are not aware of the degree to which solar costs have declined, and the emerging value that solar offers as a savings and investment opportunity, so the Going Solar in America reports are intended to build support and awareness by providing estimated values for each of America’s largest cities. Contrary to popular belief, rooftop solar is already cheaper than utility rates in 42 of the 50 cities, and this is set to increase as the cost of solar continues to decline and utility rates increase.

“We wanted to first draw attention to the financial value that solar offers today and then have a resource available to assist homeowners who are interested in taking the next step,” said Autumn Proudlove, co-author of the Going Solar in America reports.

Another reason why many homeowners are unaware of solar PV’s value is due to the fact that most people do not have a point of reference for understanding how much it costs them. This report provides customers with a common point of reference most Americans can understand well – the cost of a new (and best-selling) car.

“It may surprise many homeowners, but the fact is, the upfront cost of a typical size solar PV system, even without various policies, incentives, tax credits, and other low-cost financing options, is about the same as the upfront cost of a 2015 Toyota Corolla™ in all regions of the country,” said Jim Kennerly, the lead author and project manager for the Going Solar in America reports.

“Given that a car’s upfront cost does not include ongoing gas and maintenance costs, it really shows that going solar right now is a great financial value, no matter who you are, or where you live.”

Below is a table from the report that compares the regional price of solar (generously provided to the Center by EnergySage, an online solar marketplace), with the average prices paid for a 2015 Toyota Corolla™ (courtesy of U.S. News and World Report):

Going solar
Cost comparison between a 5kW solar PV system and a new Toyota Corolla (2014). Image courtesy of North Carolina Clean Energy Technology Center, N.C. State University.

 

To obtain a full copy of the report and rankings, please click here.

For a copy of the Technical Appendix to this report and to “Going Solar in America: Ranking Solar’s Value to Consumers in Americas Largest Cities” (released last week), please click here.
 

About the N.C. Clean Energy Technology Center

The N.C. Clean Energy Technology Center, as part of the College of Engineering at North Carolina State University, advances a sustainable energy economy by educating, demonstrating and providing support for clean energy technologies, practices and policies. It serves as a resource for innovative, green energy technologies through technology demonstration, technical assistance, outreach and training.

For more information about the N.C. Clean Energy Technology Center, visit: http://www.nccleantech.ncsu.edu.

Twitter: @NCCleanTech

Republished at JBS News with the kind permission of the report’s authours

Canal-top solar power impresses the UN’s Ban Ki Moon

Originally published at The Hindu, India’s national newspaper

UN chief Ban Ki Moon: India taking the lead in ending energy poverty

 Solar panels cover the Narmada canal at Chandrasan village, about 40 km from Ahmedabad. - The Hindu, India's national newspaper

Solar panels cover the Narmada canal at Chandrasan village, about 40 km from Ahmedabad. Image courtesy of The Hindu, India’s national newspaper

U.N. Secretary-General Ban Ki-moon on Sunday praised India’s ingenuity and cutting-edge technology while dedicating Gujarat’s second canal-top 10-MW solar power project to the nation.

The solar panels are arranged on top of the Vadodara branch of the Sardar Sarovar Project Canal, probably a first-of-its-kind project in the world to generate power.

In a brief address, Mr. Ban said he was honoured to inaugurate “this impressive project” and commended the vision of Prime Minister Narendra Modi.

I see more than the glittering panels — I see the future of India and the future of our world. This facility shows how one project can have multiple uses of conserving land and using renewables. — Ban Ki Moon

He called on India to dramatically scale-up solar power to more than 10 percent of energy mix by 2020.

For the February event on investment in renewable energy in New Delhi, he was sending his special envoy on climate change Michael Bloomberg.

He said access to energy was important to end energy poverty.

India is taking the lead in ending energy poverty and this project shows us how. — Ban Ki Moon

He praised Mr. Modi’s leadership saying this was the kind of leadership the world needed. Action and commitment can create a safer and prosperous world, he said.

S.S. Rathore, chairperson and managing director, Sardar Sarovar Narmada Nigam Ltd, said Mr. Modi’s idea led to a one-MW pilot project being commissioned on the Sanand canal in April 2012.

The new 10-MW megawatt project is on 3.6 km of the Vadodara branch canal of the Sardar Sarovar Project Canal which passes through the city. It saves land and also prevents evaporation losses. There are nearly 35,000 solar panels and the power generated is fed into the State grid and also to operate pumping stations on the canal.

The total cost of this project is $18.3 million and is financed by the State government. It was commissioned in November 2014. The Sardar Sarovar Narmada Nigam is likely to expand this project and even encourage private entrepreneurs.

‘Emerging economies must help combat climate change’ — Ban Ki Moon

U.N. Secretary-General Ban Ki-moon said here on Sunday that while respecting the principle of common but differentiated responsibilities, emerging economies such as India, China, South Africa and Brazil should take necessary action to combat climate change.

Interacting with the press after visiting a canal-top solar power project here, he said the developed countries had caused much more impact on climate than the developing nations and they had different capacities to tackle impacts.

India was taking necessary action by projects such as the canal-top power project, a creative and impressive one which all developing countries should emulate.

To questions, he said climate finance was the most important aspect to make combating climate change a success. India could play a vital role as one of the fastest growing economies.

He was catalysing funds into the Green Climate Fund, which had topped $10 billion last year. He was optimistic about arriving at a new, robust climate treaty in Paris.

India To Expand National Solar Mission

India To Expand National Solar Mission | 15/07/14
by Guest Contributor

India National Solar Mission
India’s National Solar Mission plans to bring electricity to 400 million citizens in remote regions of the country, who have never had electrical service.

Armed with a new sense of urgency to fix the problems of power supply, rising power costs, and increasing dependence on imported coal, the Narendra Modi-led Indian government is planning to enhance the country’s ambitious National Solar Mission. Currently, the mission entails installation of 20,000 MW of grid-connected and 2,000 MW of distributed solar power capacity by 2022.

Given the resource availability and the demand for solar power, tremendous capacity addition potential remains in India. The government has announced plans that it intends to source 3% of the country’s total electricity demand from solar power projects by 2022. To meet this target, a total installed capacity of 34,150 MW is required, the Ministry of New and Renewable Energy has determined. Thus, the current form of the National Solar Mission would fall short by at least 12,000 MW.

While the MNRE regularly comes up with innovative mechanisms to distribute and allocate solar power capacity among project developers, there are several areas that have not been addressed in the policy. Canal-top solar power projects, something pioneered in Prime Minister Modi’s home state of Gujarat, is among them. This would address yet another and more important problem faced by the country — water scarcity and over-dependence of the agriculture on monsoon.

Net metering and feed-in tariffs for rooftop solar power projects is another missing area. While the state government is likely to have the final say on this issue, the central government can certainly announce incentives to promote the implementation of this policy across the country. This policy has also been successfully implemented in Gujarat and had received financial support from international financial institutions such as the IMF.

Another initiative that could find place in the revised national solar mission is solar parks. Gujarat remains the leading state in India in terms of installed solar power capacity due to its 600 MW solar park, which is the largest in the world. While the MNRE had announced plans to implement several of such ultra-mega solar power projects before the new government took office, it would not be surprising if the Modi government enhances this program.

It is very likely that the “Gujarat model” will be followed for enhancing renewable energy in India as early signs point to the same. The MNRE has scheduled an investors meet in November this year where it hopes to attract investment worth millions of dollars to boost the renewable energy sector, an approach mastered by Mr Modi during his tenure as the Gujarat chief minister.

Photo Credit: Barefoot Photographers of Tilonia / Foter / Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)

This article, India To Expand National Solar Mission, is syndicated from Clean Technica and is posted here with permission.

The Solar power / Water Nexus

The Solar power / Water Nexus | 11/07/14
by John Brian Shannon John Brian Shannon

Separate from discussions about airborne coal power plant emissions, are the high levels of water usage caused by obscenely high coal power plant water requirements. Water usage by power plants are directly proportional to the downstream water loss experienced by farmers, citizens, and other water users such as wildlife.

Water used by power plants
At a time of increasing water scarcity, water use by power plants varies widely. In some regions, that different water usage level is becoming an important part of the decision-making process for planners. climaterealityproject.org

In some regions of the world, there exists acute competition for water resources as coal power station operators vie for water with agricultural, urban, and other users of water — while areas with plentiful water find their power plant choices aren’t constrained by water supply issues at all.

But the era of increasing water shortages and frequent drought seem here to stay in many regions, and the huge volumes of water required by some power plants is becoming a factor in the decision-making process as to which type of power plant is most suited for any given location.

Therefore, the conversation is now arcing towards the local availability of water and thence, to the most appropriate type of power station to propose for each location.

So let’s take a look at the water usage of five common types of power plants:

  • Coal: 1100 gallons per MWh
  • Nuclear: 800 gallons per MWh
  • Natural gas: 300 gallons per MWh
  • Solar: 0 gallons per MWh
  • Wind: 0 gallons per MWh.

While 1100 gallons per MWh doesn’t sound like much, America’s 680 coal-fired power plants use plenty of water especially when tallied on an annual basis.

The largest American coal-fired power station is in the state of Texas and it produces 1.6 GW of electricity, yet it is located in one of the driest regions on the North American continent. Go figure.

At one time as much as 55% of America’s electricity was produced via coal-fired generation and almost every home had a coal chute where the deliveryman dropped bags of coal directly into the homeowner’s basement every week or two.

But in the world of 2014, the United States sources 39% of its electricity from coal power plants and this percentage continues to decline even as domestic electricity demand is rising.

Texas Utility Going Coal-Free, Stepping Up Solar

In a recent column by Rosana Francescato, she writes;

“El Paso Electric Company doubles its utility-scale solar portfolio with large projects in Texas and New Mexico. As if that weren’t enough, the utility also plans to be coal-free by 2016.” — Rosana Franceescato

She goes on to tell us that EPE serves 400,000 customers in Texas and New Mexico and gives credit to the foresighted management team. El Paso Electric is already on-track to meet the proposed EPA carbon standard. Their nearby 50 MW Macho Springs solar power plant about to come online is on record as having the cheapest (PPA) electricity rate in the United States.

This solar power plant will displace 40,000 metric tonnes of CO2 while it powers 18,000 homes and save 340,000 metric tonnes of water annually, compared with a coal power plant of the same capacity. That’s quite a water savings in a region that has been drought-stricken in 13 of the last 20 years, only receiving 1 inch of rainfall per year.

In February 2014, EPE signed an agreement for the purchase all of the electricity produced by a nearby 10 MW solar installation that will 3800 homes when construction is completed by the end of 2014. And they are selling their 7% interest in a nearby coal power plant. Now there’s a responsible utility company that makes it look easy!

Solar’s H2O advantage

The manufacture of solar panels uses very little water, although maintenance of solar panels in the field may require small amounts of water that is often recycled for reuse after filtering out the dust and grit, while other types of energy may require huge volumes of water every day of the year.

Wind’s H2O advantage

Wind turbines and their towers also use very little water in their construction and installation, although some amount of water is required for mixing with the concrete base that the tower is mounted on at installation.

In the U.S. which is facing increasing water shortages and evermore drought conditions as global warming truly begins to take hold in North America, switching to a renewable energy grid would have profound ramifications. Estimates of water savings of up to 1 trillion gallons could be possible if utilities switched to 100% renewable wind and solar power with battery backup on tap for night-time loads and during low wind conditions.

Midway through that transition, the present water crisis in the U.S. would effectively be over. Yep, just like that. Over.

China’s Looming Water Crisis

China’s looming water crisis has planners moving to taper their coal and nuclear power generation construction programmes. You can’t operate these plants without the required water, even for a day. Yet, the people who live and grow crops and raise livestock in the surrounding areas need access to undiminished water supplies. What good is a coal power plant if everyone moves away due to a lack of water?

There are very legitimate reasons nowadays to switch to solar and wind generation — and the reduction of airborne emissions used to be the prime consideration and may remain so for some time, however, massive reductions in water consumption might now prove to be the dealmaker in some regions — and the emission reductions may now be viewed as the happy side benefit! Wow, that’s a switch!

Of course, the benefits of solar and wind power will still include no ongoing fuel costs, very low maintenance and the lowest Merit Order ranking (the wholesale kWh price of electricity) of any energy.

Granted, there are locations where renewable energy doesn’t make sense, such as some Arctic or Antarctic regions. In these places solar simply isn’t worthwhile and wind levels may not be sufficient to make the economic case. Biomass may be a partial solution in these areas and there may be the opportunity for geothermal energy — although finding ‘hot rocks’ underground near population centres is much more unlikely than many people may realize.

But in the future, the vast majority of locations will be powered by renewable energy paired with a battery backup or a conventional grid connection — or both. And its a future that’s getting closer every day.