All posts by Meredith Ratledge

Sustainability Office

Top 4 Waste to Energy Facilities

Garbage is trashy, we get it. But not anymore.

Waste-to-energy is an innovative way to think about waste management and energy diversification. Ranjith Annepu, founder of the nonprofit ‘be Waste Wise,’ commented on how public perception of this energy source could be altered.

“I think change comes with new generations and increased availability of information and public dialogue,” Annepu said.

The following waste-to-energy facilities generate energy from municipal solid waste, the kind we throw away in our garbage cans every day. Not only are these power plants utilizing this resource, they’re doing it in style.


Photo by David Castor
  1. Sysav South Scania waste-to-energy facility in Malmö, Sweden

This waste-to-energy plant is the most energy efficient plant in Sweden and one of the most carbon-friendly plants in Europe.

The plant creates electricity and heat with waste from 500,000 citizens, and it’s used to sort, store, and recycle waste. The facility processes household, commercial, and hazardous wastes.


Visulalization of the future Waste-to-energy facility by Beauty & the Bit and Ginsun Design
  1. Waste-to-energy facility in Shenzhen, China

China plans to build the world’s largest waste-to-energy plant in the world, with construction set to end in 2020.

The facility will turn a third of Shenzhen’s trash into energy, processing 5,000 tons a day. The plant hopes to combat the large landfills and illegal dumps building up in the area.

The plant’s best feature is on-site renewable energy generation. Two-thirds of the facilities large rooftop will be covered in photovoltaic solar panels.

The facility will also feature a landscaped park and ramped walkway. The walkway offers visitors a look at the inside of the facility and access to a rooftop viewing platform.



  1. Spittelau Incineration Plant

Built in 1971, a fire ironically destroyed major sections of the plant in 1987. When it was rebuilt, the new Spittelau was designed by environmentalist and artist Friedensreich Hundertwasser as a work of art.

The plant now stands as a Viennese landmark, featuring an abstractly painted building, golden ball on its chimney, and green roof. By providing district heating and electricity to Vienna, the plant heats more than 60,000 households a year.

Photo by Amager Resource Center
  1. Waste-to-energy facility in Copenhagen, Denmark

If you ever take a trip to Copenhagen in the winter months, make sure to go skiing: on top of this waste-to-energy facility.

Due to finish construction in 2017, skiers at this site will be skiing on the roof of the energy plant. And that’s not all the facility features.

For every ton of CO2 burned, the power plant will emit a giant ring of steam into the sky. The smoke rings are a completely non-toxic representation of the toxic CO2 it emits.

This serves as a visible reminder of the plant’s environmental footprint and a tangible measurement of citizens’ waste habits. As citizens become more conscious of their waste habits and recycle, they will see less rings.


Waste What: My Own Personal Landfill

We all know what trash is like- ugly, smelly, and dirty. So why on earth would I chose to carry it around with me for a day?

The minute we dump garbage into a trashcan, we are helping to creating a physical landfill. Out of sight, out of mind, right? This doesn’t have to be the case.

By carrying around my garbage for a day, I hoped to become more conscious of my waste habits. Follow along with my journal entries to discover just what exactly we throw into the can and where that trash can go.


7:30am: First things first, I need to find my mobile trash can. Luckily I’m able to put this grocery bag into reuse.


8:30am: I just created my first waste for the day. The remnants of breakfast- a banana peel and yogurt container!

9:00am: So I realized the banana peel smells, and I get to carry around that with me too. Cool.

12:50pm: After eating a salad for lunch, I now have my second source of waste for the day. I wasn’t hungry enough to finish the whole thing, so I have now added a plastic take-out box and soggy lettuce leaves to the bin.

2:15pm: Someone just asked me why I’m carrying around an old banana, as they preceded to crinkle their nose in my general direction. Looks like I’ve become a trash can too.

My personal mobile trash can

4:10pm: Documenting my most recent trash update. I did a little bit of cleaning in my pantry, so an old cereal box and two granola bar boxes are now being carried with me.

4:45pm: Went to Sugarland and got gelato, so a small plastic bowl and spoon is added to my bag. I actually accidentally tossed this into the trash can, so fishing it back out got me a few weird looks. I never realized that throwing trash away is such compulsive behavior. We really don’t give our waste habits a second thought

6:30pm:  I was starving for dinner, so no food waste here. Luckily the restaurant will be washing their bowl, cup, and silverware for reuse. Unfortunately they did print a receipt, so that was added to the bag.


9:00pm: Status update- just finished off a gallon of lemonade!


11:15pm: Just did some homework, so I’ve added old scrap paper and a mechanical pencil. I’ve concluded that this should be all of the trash I will be generating for the day. At least I hope so, otherwise I might need another bag soon. Let’s see how this breaks down:


The best way to manage trash is as follows: reduce, reuse, recycle or compost, create energy, and finally, landfill.

When considering their own habits, consumers should recognize that reducing consumption is the best way to manage their waste. Landfilling should be the last possible option consumers should consider.

The first pile to the far left includes materials that should be sorted and composted- the banana peel, salad, and organic nut bar. The salad container should then be recycled, and the bar’s packaging sent to the second pile.

This second pile includes trash that can be used in a waste-to-energy facility- old paper, bags, etc. However, this trash would first be sorted by the facility. They would ensure no harmful plastics and other materials that would create unsafe air pollution are used in generation.

The final pile includes broken down cardboard boxes, a gallon jug, yogurt container, and magazine. These items should be recycled so their materials can be put into further use.



FAQ: Waste to Energy?

The trash we create every day is a resource that sits idly in landfills, generating methane emissions and seeping into the ground.

But what if this waste could be used for something useful?

Waste-to-energy is an alternative to traditional waste management. Many countries around the world have begun to turn to waste as a source of energy creation.


How does waste-to-energy work?

The most common process involves burning waste to create energy. This trash is referred to as a municipal solid waste source.

Trash enters a plant, is sorted, and stored until use. Waste-to-energy (WTE) plants remove hazardous and recyclable materials before burning.

Trash is added to boilers, where combustion creates a heat or electricity product. The ash by-product, if clean enough, can be used a raw material in other industrial processes, as in road construction.



Doesn’t that create an air pollution problem?

Like any other power producing plant, waste-to-energy plants generate carbon dioxide emissions. However, these facilities can actually help reduce CO2 emissions.

Ramesh Shankar from University of North Carolina at Charlotte, shared his thoughts on the matter.

“[Waste-to-energy facilities] produce less CO2 per megawatt hour than coal, oil, and natural gas.”

In addition, these facilities help avoid harmful effects of landfills. When trash is sent to landfills, during decomposition it produces methane. This greenhouse gas is a much more potent heat-trapping agent than carbon dioxide.

Waste-to-energy facilities can also help avoid issues of land use. In major cities, finding room for landfills can become a concern. Toxic chemicals from landfills can leak into the ground and contaminate ground water supply.

Morton Barlaz, Head of Civil, Construction, and Environmental Engineering at North Carolina State University also addressed air pollution concerns.

Baralz stated that “Modern waste to energy combustion facilities have state-of-the-art pollution control and I consider them to be a clean source of energy.”


 What does the current marketplace look like for waste-to-energy?

Waste-to-energy is being increasingly considered as a way to diversify energy generation. As many countries attempt to reduce coal use to fight climate change, alternative options are considered.

According to political standards, some countries have more incentive to invest in waste-to-energy generation.

Shankar stated that “Some countries have the cost of CO2 factored in their system so that it incentivizes non- or less-carbon emissions.”

Shankar explained these countries may also be more socially responsible, depending on the amount of available land and a commitment to conservation. He commented that Scandinavian counties seem to be at the forefront of waste management.

“Sweden has to import trash because they are so efficient in disposing their own,” he said.

Sweden is the current leader in waste-to-energy production, with over 99 percent of all household waste avoiding landfills. Western and Northern Europe, Japan, Taiwan, and the USA also remain leaders in solid waste management.


So, the environmental and economic impacts outweigh the costs?

It depends.

Ranjith Annepu, founder of the nonprofit ‘be Waste Wise,’ explained an important factor is local conditions.

“For example, if the organic percent of the waste stream is higher than 50%, then WTE is not suitable,” he said.

Annepu also explained that feasibility depends on regulations and tariff fees for electricity in place.

Blair Pollock, Solid Waste Planner at Orange County, North Carolina, cautioned against waste-to-energy as the primary management form. When considering waste-to-energy, Pollock said this should not be a substitute for other forms of waste management.

In the waste hierarchy, reduction and recycling measures always come first. This is more energy and pollution efficient than generating energy from trash. He cautioned that waste-to-energy should not be treated as an alternative that would decrease recycling rates.

Pollock also considers two questions key in the waste-to-energy process.

“Have you retrieved most readily recyclable materials and taken out potentially contaminating type fractions?” Pollock said. “And are you burning it in the most efficient and environmentally sound manner possible?”

Food for Thought: Real Questions on Biofuels

To provoke conversation on biofuels’ future in the energy industry, questions need to be answered.

Students at the University of North Carolina at Chapel Hill were asked what their questions on biofuels were to help gauge a common understanding of the marketplace.

Students shared positive attitudes towards biofuels. However, some confusion remains as to the specific value of biofuel investment. Below are the questions posed by students.


“What are biofuels? And I’m not looking for a simple definition- I want a more in-depth explanation.”

Duoyun Zhou, from Shanghai, China, Class of 2018.
Duoyun Zhou, from Shanghai, China, Class of 2018.

Biofuels are fuels derived from the living matter of plants and animals. This matter typically refers to plant matter such as grasses, algae, or agricultural residue. This can also include animal fats and waste.

These materials are commonly referred to as feedstocks, or the raw materials used to create the fuel product. This biomass can be converted into various fuels, chemicals, and materials.

The conversion of biomass into a fuel product involves the use of microorganisms for fermentation. The fermented product is then created into a biofuel. The fuel can be used in a diesel engine and blended with traditional fuels.

There are major advantages of integrating a bioproduct in our fuel supply. A biofuel market will decrease the use of fossil fuels in our oil supply for conventional automobiles.

An increase in demand for biomass materials will necessitate an increase in farming practices to meet demand. By creating such a market, rural economies are supported while dependency on foreign oil markets is reduced.

This product results in a cleaner fuel supply that will improve air quality as well as human health.


“Where can you get biofuels? Where is this supply coming from?”

Gursheen Kaur, MBA Class of 2017, from India.
Gursheen Kaur, MBA Class of 2017, from India.

Imagine that at your nearest gas pump, biofuels are the fuel source used to power your car.

The imagined scenario is already partially true–ethanol, a corn based fuel, is part of the traditional fuel mix in the United States. In the future, more competitive feedstocks can be integrated into the mix as well.

If biofuels experience successful market introduction, biofuel access could be so integrated it would go unnoticed by the average citizen. As drilling for oil becomes less economical, biofuels will become more competitive and will slowly become a larger portion of supply.

The three main biofuel products in the global market are bioethanol, biodiesel, and biogas.

Jordan Kern, Professor with the Institute for the Environment at UNC Chapel Hill, explained there is not one optimal feedstock choice.

“It depends on where you’re growing it and the resources available,” he said.

Jay Cheng, Professor of Biological and Agricultural Engineering at North Carolina State University, shared his thoughts on the matter.

Cheng explained that Brazil has a large bioethanol industry that accounts for approximately half of all automobile biofuel. Brazil’s success story in the biofuel industry goes back to the resources available to the country.

Cheng said their success was mainly due to their relatively cheap and high-yield sugarcane.

“What is the United States doing in the biofuels industry?”

Jinming Lin, from Memphis, Tennessee, Class of 2019.
Jinming Lin, from Memphis, Tennessee, Class of 2019.

Currently, biofuels provide about 1 percent of total United States’ energy needs. Ethanol, the primary biofuel in the US, is more expensive than gasoline on an energy content basis.

The United States government hopes to make this alternative energy source more economically viable. The US Energy Department plans to fund developments in biomass technology.

In January 2016, the department announced that 15 million in funding will be provided through 2020. Applicants hoping to capitalize on the opportunity must address technology improvements in processing and productivity.

In addition, the industry will be bolstered by military investment. In 2009, the Navy broadcasted that by 2020, half of fuel sources would be non-fossil fuels.

Since then, aircraft and ships have been have been powered by beef fat, municipal waste, palm oil, and algae. This aligns with the military’s commitment to security by reducing reliance on foreign oil.

Cheng also expressed a potential for the United States to utilize local biomass. A large amount of “wood pellets (are) shipped to Western Europe from southeastern states of the US for bioenergy production.”

Cheng thinks that the United States could better use this resource in order generate bioenergy as well as local jobs.


“What problems will you face in implementing biofuels?”

Abhaya Pratap Singh, from India, MBA Class of 2017.
Abhaya Pratap Singh, from India, MBA Class of 2017.

Unfortunately, biofuel production involves several drawbacks in terms of environmental best practices and industry infrastructure.

The largest environmental barrier is that large amounts of land are not readily available for the production of feedstocks. Biofuel production can lead to increased food and land use prices.

Biofuels create competition for land-use with food production. Increased crop-demand causes the price of those crops, and thus food derived from those crops, to increase. Meat and dairy product prices also increase, as it becomes more expensive for farmers to feed their livestock.

An increased demand for crops also leads to increased deforestation and destruction of natural habitats. This not only displaces indigenous peoples and endangers wildlife, it releases greenhouse gases into the atmosphere, contributing to climate change.

Fortunately, algal biofuels can address many of these issues because it does not compete with food for land use. Algal biofuel is a more expensive biofuel option. However, algal fuels could avoid issues of higher food prices and destruction of natural habitats.

Kern stated the issue surrounding infrastructure is a “chicken or the egg” kind of conversation.

He explained that the companies that refine fuels are different than those that produce cars. He illustrated no one will build a biofuel production facility if there are no cars on the market that can use the fuel.

Currently, issue also surrounds biofuels’ ability to compete with traditional fuel products.

“One of the main challenges for biofuels is the scale,” Cheng said.

He explained that most production facilities are small in size. This occurs “because the cost of the raw material transportation would be too expensive if the facility is big.” In contrast, most fossil fuel production facilities are huge, which gives fossil fuels a “competitive advantage.”

However, Cheng also noted that fossil fuel resources are limited, “and the cost for biofuel production is getting lower.” He expressed that in time, biofuels will become a better fuel option.


Friend or Foe: Big Players and the Renewable Industry

Many businesses are capitalizing on a growing clean tech opportunity in North Carolina- renewable companies, city developers, and venture capitalists. Large energy providers are often left out of the picture, perhaps as they’re perceived as heavily invested in fossil fuels. However, this may not be the case with the coming energy transformation.

Below, two Duke Energy representatives provide insight on Duke’s sustainability efforts. Elizabeth Bennett is a manager of the Distributed Energy Resources Group, and Hilary Davidson is Duke Energy’s Director of Sustainability and Community Affairs. Both shared their perspective on the role of sustainability in energy supply.

This Q&A explores the challenges and opportunities that renewables present for Duke Energy. The representatives also discuss Duke’s future plans to expand its sustainability efforts, bringing awareness to shifts in the energy market. (These interviews have been edited and condensed for clarity.)

Q: What trends do you see in renewable energy policy and the growth of big businesses? Do you have any insight on the future nature of the renewable industry ten years from now?

Elizabeth Bennett: I think questions about policy incentives are going to become less and less important because the economics is working.

Now it’s working differently for different customers. I know Duke would like to get to a point where we are able to connect customers with affordable solar options — and by customers I mean your big-box retailers but also your residential customers.

If you look over the border on what we’re doing in South Carolina, there’s a good example. Through legislation we have a way to invest and provide customers options for solar engagement. And we’ve rolled out a rebate program for rooftop and ground-mount installation on customer properties.

We’re also going to be rolling out a shared solar program. So for folks that live in apartment complexes, or that might not have a roof that’s conducive with solar, or that might not want to deal with the operations or a homeowner’s association that doesn’t like solar on the roof, then they can participate in the shared solar concept, or community solar.

So those are the kinds of things we at Duke would like to be able to invest in and provide for customers in the future. And I think there is going to be a pathway to do that. Now every state will be a little different, and that’s where policy comes in.

I would be careful not to look at a tax crediting expiring and say, ‘It’s the end of solar.’ And I think some people did, but it’s not slowing anything down. And especially with the federal government’s decision in the end to extend the ITC — that was significant. And I don’t think that’s being talked about enough.

And the only other thing I’ll say, and it’s somewhat obvious sometimes — a lot of people tend to forget that North Carolina ranked number two last year in terms of solar growth. And we are really proud to have been part of that.

Last year we constructed four large-scale solar facilities totaling 141 megawatts, and late last year we announced another 75 megawatts. And so our pace isn’t slowing down.

And I think as we look towards the future, if there’s anything to take away, it’s that we believe the utility has a big role to play in investing in solar and other renewable resources: bringing those to customers in an affordable and a reliable way, and growing them as part of our portfolio, but also balancing with the other resources we have and the other demands we have on the system.

Q: Why does sustainability make sense for Duke?

Hilary Davidson: It makes so much sense. It makes sense socially, economically, and environmentally. People always think, oh, it’s going to cost money to do sustainability things.

It really is all about long-term— making good business decisions that are good for the environment and good for people. It really saves you money.

One of the key things we really encourage folks internally— when we talk about sustainability, you start thinking differently when you think about conserving those resources. (Employees) think of new processes, they get very efficient, and they come up with new ideas. We have saved millions of dollars with employees with new innovative approaches of how they do their job.

And we have a group we call the Sustainability Corps, we kind of named it after the Peace Corps. And it has been really fun. So they have gotten energized and really saved so much money through their projects.

So you can reduce emissions or water and also costs and your budget. We quit tracking the numbers because it’s so embedded now because it’s so much a part of the culture.

Q: How much of these sustainability efforts are a reaction to the growing environmental movement and pressure from your customers for more responsible practices? Does this make your efforts relatively recent?

Davidson: We’ve been doing this a long time. I would say it’s not a reaction for us, and I can say that so passionately.

I’ve been doing this for 30 years at Duke. I helped write the first environmental report, and that was in 1993. Duke created the first environmental science center of all of the utilities in the 1970s.

So they’ve had a huge environmental focus for a long time. So that first external environmental report was kind of unique for utilities. That was not something that was typically done way back when.

So the whole movement changed. It was environmental for a while, and then social responsibility started, and then the name sustainability actually formalized — we formalized a corporate sustainability office in 2008. So we formalized the name at a certain point, but it’d been there in one form or fashion.

One of the things I’d like to say, you know, J.B. Duke, the founder of Duke Energy, started the Duke Endowment, and this was back in the 1920s. When he started the power company, he said, hey if I’m going to make money from this industry, I’m going to also give money and philanthropy back to the Carolinas and the community, which to me is sustainability.

So he started the Duke Endowment, which today is one of the hugest endowments, and it gives money to the Carolinas. To me, the foresight of that is just part of that whole philosophy.

Q: What opportunities and challenges have renewables presented to Duke?

Davidson: I think it has been another great asset to add to our diverse fuel mix. I think having diverse fuel options is our biggest asset and will continue to be our biggest asset in the future.

I think we always want to have a diverse fuel supply. We don’t ever want to go a single source of anything. I think just like a diverse stock portfolio, it keeps you healthy, and serves you well over time, so should a diverse fuel portfolio.

I’ve been in the industry long enough to see — I was around when gas prices went sky-rocketing, I was standing at gas lines in the 70s to fill up my gas tank, I’ve been around when Chernobyl happened, when Fukushima happened, I’ve been around when natural gas prices spiked. I’ve been around now with the shale-gas revolution, with how cheap gas is now.

You know, solar is fantastic. But I don’t know, something could happen with solar that we don’t even know yet. Sometimes we think everything is glorious, and sometimes things happen. So I guess keeping all options on the table is good.

The challenge of renewables for now, I would say, is storage. And from what I understand right now, the storage technology is not totally there yet, and also there is the expense of it. The sooner we can get there at an affordable rate is awesome. Understand we own about 15 percent of the utility-scale storage in the United States right now.

The other thing with the challenge with renewables is that it doesn’t always match the peak. And I think people don’t always understand that, it’s not always there at the right time. It’s intermittent, and that’s an issue as well.

Q: A quote from Duke’s 2014 sustainability report- “closing 40 coal-fired generating units… We’ve also invested more than $4 billion in wind and solar facilities and, in 2014, we committed $500 million to expand solar energy in North Carolina.” Oftentimes, there is a negative perception surrounding Duke because a large percentage of your generation is from coal. Their comment might be you could do better to invest more in renewables and efficiency. What would be your response to that?

Davidson: I guess what I would say to those people is please consider the entire population in North Carolina and the needs of your neighbors in this state.

Our customer base is not a high-income customer base. Those people cannot afford to have all of that power shut down and do really expensive renewables. You can’t just transition and shut everything down and pay off-site prices right now.

That wouldn’t make economic sense. Just like anything you need to transition. The path you are on is transitioning to a lower-carbon economy and future.

And that is the pathway underway; and you do it sensibly, and in a way that is not hurting people. You do it in a smart and economic way as those prices come down and as technologies come up.

One of the things with Duke — our stakeholders are everybody. So they’re all at complete different ends of the spectrum, and at the end of the day we have to keep those lights on for everybody.

We respect all of the different viewpoints that there are, truly. We do have the extreme activist end of things, where they want everything totally green right now. If you look at the entire population it’s actually not a high percentage of what most of customers actually want.

Most of our customers say, we really want an affordable bill because we’re just trying to survive, and I need to stay in business in this state. So there are some heavy social issues that are going on. And that’s obviously very critical.

There are health issues, there’s social issues, education issues, which is all part of sustainability. Those are equally important as the environmental and green part of it. And so that’s what you have to think about.

Really when you think triple bottom line, you need to be thinking of all of those in the long-term, and not doing a drastic reaction to just one component of it and sacrificing other things. People might not like you, and you might get beat up for it. But you still need to do the right thing to make sure no one is getting hurt in the long-run.

Student Enthusiasm for Biofuel Potential

In order to provoke conversation on the future of biofuels in the energy industry, students at the University of North Carolina at Chapel Hill were asked, “What are your thoughts or opinions on biofuels as an alternative energy source?” Positive impressions seem to be had of the industry, especially in terms of environmentalism and long-term sustainability. However, some confusion remains as to specific value in biofuel investment. Below are the comments shared by students.

The Future of Algae in the US

The world is becoming increasingly more aware of the climatic tipping point on the horizon. Fossil fuel use makes our atmosphere increasingly more vulnerable. As carbon dioxide is emitted, climate change put the environment and human health at risk.

World energy leaders are looking to investment in alternative options to control greenhouse gas emissions. Algal biofuels provides such an alternative energy source for traditional liquid fossil fuels.

Algae’s renewable source potential lies in its high productivity as a biomass. Harvested oils from algae is turned into fuel for transportation.

Thus far, algal biodiesel is not efficient enough to be competitive in the energy market. There are still limits to the technology that require further research. The United States government hopes to make this alternative energy source more economically viable.

The US Energy Department plans to fund developments in biomass technology. In January 2016, they announced that 15 million in funding will be provided through 2020. Applicants hoping to capitalize on the opportunity must address technology improvements in processing and productivity.

Until technology barriers are addressed, large-scale introduction is a long way off. Exxon, the world’s largest diesel producer, noted in 2013 that viability was over 25 years away. They have recently undertaken a project to produce an algal fuel source.

Current low oil prices makes algae integration into the fuel supply unlikely. However, the biomass industry should also hope to gain momentum from the new federal regulations.

Under the Clean Power Plan (CPP), the EPA has created partnerships with states. The plan’s ultimate goal is to reduce United States carbon emissions. The hope is to reduce the harm to the atmosphere before climate change becomes uncontrollable.

In the agreement, power plants, the main source of CO2, are held to emission standards. One way that plants can expect to cut emissions is from carbon capture and utilization. This spells good things for the algae industry.

The plan creates opportunity to build algae farms with power plants. Excess CO2 can cultivate algae growth. Apart from on-site additions, as states comply with the CPP, new algae farms could be built.

Some areas of the United States have also taken environmental incentive to make the investment. California passed Assembly Bill 590 in order to support the biomass industry.

This would give Greenhouse Gas Reduction Funds to these facilities. This support derives, in part, from California’s reliance on forest-derived biomass.

In addition, the industry should expect returns from military investment. In 2009, the Navy broadcasted that by 2020, half of fuel sources would be non-fossil fuels.

Since the announcement, aircraft has flown on many biofuels, including algae. This aligns with the military’s commitment to security by reducing reliance on foreign oil.

These aspects all play a part in the future of the algal biofuel industry in the United States. The industry will only grow as further research is accompanied by increased investment.