Distributed Energy Production

February 20, 2022

By Rob Redfearn.  (04/25/2019)

Energy Islands Bring Power to the People

TerraStar Energy (Lumberton, NC) has recently entered into agreements with developers and government agencies in 3 East Africa countries - Ethiopia, Kenya and Burundi - to provide commercial-scale renewable energy power plants that combine solar and waste-to-energy technologies. These projects have been greenlit and the company is in the process of finalizing designs and working out permitting and financing. They form the basis for the company’s new Energy Island concept of power generation.


TerraStar Energy was founded in North Carolina in 2011 by entrepreneur, business developer and builder Rob Redfearn. Redfearn first became interested in the green energy space in 2008 and soon dedicated himself to delivering a solution to affordably convert manure from Southeast North Carolina’s 2300 hog-farm operations into energy. Since then, TerraStar Energy has evolved and expanded its business plan and has received solicitations from nearly two dozen countries. They are now developing projects in eleven countries ranging in size from under $3M to over $100M, with partner-developers assisting in each. During the process, TerraStar has aligned itself with a sister company, Renen Energy in South Africa, and with numerous manufacturing partners in Europe, China and India.


TerraStar plans to equip industry, large commercial users and communities with “Energy Islands” - solar arrays, with modular gasifiers and anaerobic digesters, designed to be fueled with assorted outputs common in industry and agriculture as well as municipal solid waste (MSW). All commercially-proven, the 3 technologies work together in concert to provide energy without interruption at an attractive cost per kWh . Solar energy is deployed worldwide and is supplying an ever-increasing percentage of the world’s energy use, thanks to an explosion in affordability - hardware costs have dropped 80% since 2008 - it can deliver very inexpensive power. It’s disadvantages, however, are obvious: with current storage limitations, it  cannot offer a suitable base-load system on its own.  Battery storage for continuous commercial use at night and on cloudy days is too costly an alternative. Until storage costs dip below the cost of new generation, it will not be a marketable option.


Converting biomass and garbage into energy via gasifiers and anaerobic digesters to supplement daytime solar energy alleviates the need for batteries and can supply a steady balance of energy throughout the day and night. Used together they reduce the amount of solid waste that goes to a landfill by 90% and will help reduce the trash that ends up in our oceans. By replacing coal and natural gas power generation and mitigating the methane that landfills emit they will help curb greenhouse gas emissions.


Paradigm Shift

In Redfearn’s words, “The key to our program is not so much the technologies themselves - those are already proven commercially at scale - but rather our unique business plan. First, we are combining several technologies on the same site. Second, we use modules that can be coupled together rather than monolithic structures that are engineered from the ground up, so our systems can be built easily and quickly.  Our ‘sweet spot’ is relatively small power plants of 2-10MW capacity. At these small scales we can still produce a kilowatt of power for the same or less than most fossil fuel plants, but since the units/modules are scalable, we can deploy them almost anywhere and use almost any kind of fuel, including what would otherwise be thrown away. Recycling waste back into energy makes economic and environmental sense.


Third, and maybe most importantly, we are bringing energy production down to a local level and creating new shared business opportunities for entrepreneurs. This disruptive business model further democratizes energy production that rooftop solar arrays initiated. Energy in our opinion is a basic human necessity in the twenty-first century and we think our business model is the best way to ensure as many people as possible can have access to it as well as profit from it. The best and fastest way to grow our business is to have hundreds and eventually thousands of local owner-operators, each managing an Energy Island under a standard operating plan, each employing a local workforce. They can each solve local waste and energy problems that they themselves live with and understand.


This makes our concept perfect for places such as Africa, where economies are growing and demand is unpredictable and spotty. It is also difficult there to attract capital to build 200MW power plants with expensive transmission and distribution lines. We can start small and add on as required enabling these communities to leapfrog into the global marketplace. At the same time, Energy Islands can be used in developed economies that need incremental capacity boosts to certain sectors of their grids.”


Over the last ten years, TerraStar has worked to nurture a team of partner-developers who live and work in the areas they are developing. In addition to several countries in Africa the company has partners in Mexico, the Caribbean and North America. This gives the company the local content certain countries require from foreign investment as well as local intelligence and local management. In return, the partners will share in the equity and profit of each plant.


Modular and Scalable

TerraStar has set up Asian and African manufacturing partners and is currently establishing manufacturing connections in Mexico as well.  TerraStar’s gasifier and digester modules each are comprised of different factory-built components which are quickly plumbed together on a prepared site. The site work itself is generally uncomplicated, consisting mostly of grading and concrete slabs and footings. Ancillary equipment (sorting equipment, shredders, dryers, milling, etc) is also modularized. Prefabricated steel buildings to enclose the projects are shipped ready-to-assemble. All this helps to keep capital costs low, while simplifying and speeding installation, compared to a traditional power plant.


Effectively “plug and play”,TerraStar can build their power plants almost any size, almost anywhere, with installs in as little as a few months. . A typical Energy Island suitable for 100 tons of waste per day (typically generated from a community of about 50,000) would have 1-2 MW of solar combined with a 1-2 MW digester and a 2-4 MW gasifier array. It could also be half or ten times that size, depending on the site specifics and availability of fuel and the local demand for power. The size of the solar array, the number of digesters and gasifiers can be adjusted easily and affordably from the outset, or over time, depending on the scenario.


TerraStar receives inquiries weekly from around the world and two themes are always the same: communities need a stable and consistent supply of affordable energy and they have a serious waste management problem. TerraStar’s plan solves both of those problems while offering a negative carbon footprint.


Reducing Greenhouse Gases

Gasification and anaerobic digestion have been around for a long time but have found a growing market now that global warming, combined with overflowing landfills are significant problems. Gasifiers extract energy from stuff like wood, plastic, paper, textiles, and rubber making it a great way to convert municipal landfill waste into energy. Anaerobic digesters use bacteria to “eat” biomass like food waste and septic waste, in the process of releasing methane. The gases from gasification and digestion can be used to generate electricity. This replaces the use of fossil fuels and the processes themselves release very little greenhouse gas.


The cultivation of fuel crops suitable for digestion and gasification- crops like miscanthus grass, bamboo, and other woody materials - recaptures atmospheric CO2. When converted to energy via modern waste-to-energy technologies a majority of this trapped carbon is left behind. Using municipal solid waste as a fuel stream, including plastics which are often impossible to recycle, keeping it out of landfills and oceans.. Landfills are the third-largest emitter of methane in the USA., a greenhouse gas 20 times more potent than CO2.  Intercepting the waste and harnessing the energy from it keeps the methane earthbound.


A typical 10MW power plant can consume up to 130,000 tons of fuel crops in a year which have themselves removed 400,000 tons of CO2 from the air. Using gasification and digestion most of that carbon is conserved as a solid. Put back into the ground as fertilizers and soil amendments it permanently eliminates airborne carbon. In the meantime, it replaces a nearly equivalent volume of coal which would have produced up to the same 400,000 tons of CO2. So combining fuel crops with gasification and digestion has a multiplier effect on reducing climate affecting gases.


Considering the unmet demand in Africa for energy is measured in gigawatts, and the conditions there being perfect for growing a range of fuel crops, the opportunity to sequester massive amounts of carbon while eliminating solid waste is immediate. Hundreds of energy islands could easily help to reduce greenhouse gases within just a few years.


Decentralized and distributed energy production

A typical natural gas power plant needs to be 100 or more megawatts in size to deliver power at a cost-effective price point,. They cost hundreds of millions of dollars and take years to build. TerraStar can deploy and construct their power plants at scales of 2 MW or less and still produce power at a competitive rate per kWh. Therefore, they can build many small power plants, closer to the fuel and closer to where the customer needs the power, ideal for environments where delivery infrastructure hasn’t yet been constructed. Fuel does not have to be transported from distant mines via rail and pipeline and less electricity is lost in the transmission from the power plant to the end-user. Overall, the efficiencies from beginning to end are superior to the current fossil fuel paradigm.


The end result is a secure energy network less prone to disruption, delivering the maximum amount of energy with positive environmental effects at a cost comparable to what the market is already used to.


The Economics

TerraStar can build a power plants from 1 MW in size up to 100MW or larger. The combined cost of equipment and on-site work, as measured as a cost per kW of capacity, is $3500-4000, on a par with natural gas plants which have to be much larger to achieve their economies of scale. Based on typical feed-in tariffs, the rate of return on investment is better than solar and fossil fuel plants so to be attractive to investors. An Energy Island’s fuel cost is low because much of it is MSW and other types of waste.


Ironically, TerraStar’s key benefit is the small size and low cost of each power plant and most lenders are looking for bigger, more expensive projects. “A single 4MW power plant at somewhere south of $15M is not going to be attractive to them”, says Redfearn but he believes that investors will see the benefit in the fact that they can build dozens of units at similar cost points. “The scalability of the business plan should help to attract institutional investors, since they can invest in one, ten or twenty plants and multiply their returns accordingly and proportionately”, he says.


In fact, scaling the entire business is as easy as scaling an individual plant; building more Energy Islands can be as easy as building fast-food restaurants. In fact, Redfearn (a former Dairy Queen franchise owner) has modelled the business plan similarly to that industry: small, locally-owned and managed power plants all operating under a common banner and standard operating plan designed to maximize efficiency and profitability.


It is Redfearn’s hope that this model will speed market penetration and coincidentally have quick and significant effects on helping to stem climate change.


The Technologies and Process

At each Energy Island site, incoming waste is sorted to remove metal, glass, and mineral materials. Soft and wet materials (food and septic waste) is segmented to be digested by bacteria. Hard and dry materials (plastic, paper, wood, textiles, cardboard) are shredded, dried to 20% moisture, milled and then compacted into briquettes which can be stored until they are converted into energy.


TerraStar’s anaerobic digesters are a smaller and simpler design than most others on the market and are based on a design from the University of Denver. They have shorter retention times, higher throughput, and smaller footprints. They are modular and their cost is less overall than competitive designs. Methanogenic bacteria consume the solid matter and emit methane which is collected and used in generators or turbines. Residual digestate is a good organic fertilizer that in turn can be used to grow more fuel crops.


TerraStar’s gasifier modules consume up to 1.5 tons of feedstock per hour per MW. The amount of energy per ton depends on the actual feedstock, as different materials have different inherent energy values. Under high heat but with restricted oxygen, the molecular bonds of the solid material are broken and volatile gases are released. Those gases - largely hydrogen and methane - are captured and used in generators or turbines. Residual carbon called biochar can be enhanced with NPK to be used as fertilizer or sold on the spot market.


During the day the generators can be set to operate at a lower rate as the solar power is at its peak. As the sun goes down, the generating cycle can be increased. Balancing the output from the three sources allows for steady and dependable power output.



The Energy Island concept makes perfect sense in developing economies where access to a reliable source of energy is required for growth. The concept also makes sense in mature economies where dealing with waste has become a serious and expensive problem. If there were one or two such energy islands in every community in the world, there would be a drastic reduction in both pollution and greenhouse gases and a movement away from large centralized power generation facilities which are monopolizing and antiquated as well as unaffordable for small local markets.



●       TerraStar’s Energy Islands use plug-and-play modules that can use a variety of feedstock including MSW and locally grown fuel crops, reducing landfill use and creating carbon sinks.

●       We can build them almost anywhere at almost any scale that matches the energy demand and availability of locally produced fuel. Their energy security therefore will not be dependent on foreign fuel.

●       Combining solar arrays with biogas and syngas provides electricity 24/7/365 at a cost per kWh comparable to Natural Gas and coal but without the GHGs

●       The byproducts of the digesters and gasifiers are fertilizers and soil amendments that can be cycled back into the ground to increase agricultural output, including more fuel crops.

●       Using small powerplants and microgrid technologies instead of high investments in transmission and distribution lines, we can "leapfrog" these regions into energy security they need to build their economies. Much the same way cellular technology spared them the cost of installing hardwires for communication.

●       Using waste to produce energy gives trash a value, so less of it will find its way into the environment.

●       Decentralizing the energy production is more efficient since it puts the generators nearer the fuel and nearer the consumer, saving on transport costs and reducing losses in transmission.

●       Jobs are created locally at the plant and in fuel crop cultivation. Ownership opportunities for local entrepreneurs are likewise created.

●       Energy is something needed for economic activity. New sources of energy can be leveraged many times over to vastly increase gross domestic product. This opens many doors for expanding economies thus far deprived of consistent, reliable and affordable energy.

●       Fully absorbed costs of electricity from TerraStar Energy Islands are low enough to offer an excellent return on investment, so the business model does not depend on government subsidies or charities to be viable.