Category Archives: renewable energy

Anaerobic digestion solution for waste & energy

Anaerobic digestion

Anaerobic digestion (AD) can be used for farms, businesses and municipalities as a productive solution to a growing waste problem throughout the world. In addition to AD, waste-to-energy is done in landfills using landfill refuse and landfill gases (such as methane). The use of AD in a biomass plant is a cost-effective way to produce renewable energy. AD also leads to less landfill waste and is a constructive way for farms, businesses and municipalities to dispose of waste. AD is the process of turning agricultural waste (such as livestock manure), wastewater, or municipal, commercial and industrial waste streams (such as food processing waste), into energy. AD uses micro-organisms to break down organic material and create biogas (biogas consists mostly of methane and CO2).

Instead of waste simply ending up in landfills, or being incinerated, waste can be turned into energy. Farms can be entirely powered by waste from their livestock, food waste and wastewater. Use of AD can make also make wastewater treatment facilities energy neutral or even energy positive, translating to huge cost savings for municipalities.

Organic waste finds a purpose in an AD biogas plant, as it is put in a digester, along with various types of micro-organisms (enzymes, bacteria etc…), to transform the waste into energy (methanation). The molecules of the organic material are broken down in the plant into a useful form like glucose. The “digested” raw material is then used to create biogas (and digestate which can be used as fertilizer).

The biogas can then be purified (and also optionally be upgraded with hydrogen) and turned into pipeline-quality synthetic natural gas for the grid. Biogas can also be turned into compressed natural gas (CNG) for vehicles. The anaerobic process also occurs naturally (as in landfills), in addition to the man-made construct in a biomass plant.

An anaerobic digester and biomass plant generate biogas (and/ or biomethane) which can be burned on-site to generate heat, power or both (so, combined heat and power – CHP). AD is mostly used by farms and wastewater treatment facilities for on-site electrical and heating generation, although it can also be used in a variety of other applications. Biogas can also be purposed as an energy source for the grid when purified, and turned into pipeline-quality synthetic natural gas (or turned into biomethane and used for heat or transportation as CNG). Also produced in the process is digestate, which is a source of nutrients that can be used as a fertilizer.

Biogas can also be upgraded with hydrogen, combining the outputs of a biogas plant and an electrolyzer, creating biomethane. Like conventional natural gas, biomethane can be used as a transportation fuel in the form of compressed natural gas (CNG), or liquefied natural gas (LNG). When biogas is used for heat or transportation, as biomethane, CNG, (biomethane – CNG – can be used in place of diesel, given modifications to the vehicles in question), there are tremendous greenhouse gas reductions.

The entire bus fleet in Oslo, Norway, is run on CNG from sewage treatment and organic waste, and they see a dramatic (around 70%) reduction in greenhouse gas (GHG) emissions compared to fossil fuel burning vehicles. Food waste and other waste processed through AD also brings the benefit of reducing GHG emissions substantially by reducing landfill waste. When AD is used for on-site electrical generation, energy generation for a municipality, farm or wastewater facility, GHG emissions overall are greatly reduced. Energy produced by AD has a very low overall carbon footprint.

Poplars AD plant

Poplars AD plant

The AD plant at Cannock, Staffordshire, England (called the Poplars AD plant) is an example of a successful, large-scale AD plant. The £24 million project treats commercial and industrial food and waste to create, through methanation, around 6MW of renewable energy, synthetic natural gas, for the national grid. The Poplar plant shows that a large-scale anaerobic digestion project is viable. AD has been successful in many commercial operations as well. For example in Orlando, Florida, food waste sourced primarily from the Walt Disney World Resort is fed through an anaerobic digester, producing enough electricity to meet the needs of over 16,000 homes.

Please see: renewable energy: biomass and biofuel

Gasification – syngas from fossil fuels and environmentally friendly versions

Algae : the future of biofuel

Cellulosic biofuel – one fuel option

The Block Island Wind Farm

The Block Island Wind Farm – America’s ONLY operational offshore wind farm

The Block Island Wind Farm, in Rhode Island, ACTUALLY is America’s ONLY operational offshore wind farm. This wind farm was built by Deepwater Wind for $300 million, and is 4 miles off the coast of Block Island, RI. – CLICK FOR MORE INFO. ON THE:  Deepwater Wind Block Island Wind Farm

It is only 30 MW. In comparison, the London Array offshore wind farm is 630 megawatts and powers “half a million UK homes every year, which works out to two-thirds of the homes in Kent”.(source :


Scotland recently powered most of their country with wind energy, along with countries like Germany, Denmark, and Ireland (and much of that is offshore wind energy – 5-countries-leading-the-way-toward-100-renewable-energy)

Americans who discount offshore wind energy (or wind energy in general), in favor of an energy mix including dirty fossil fuels, might want to consider this energy source as a higher priority. What do you think?

solar concentrating plant

The largest solar concentrating plant in the world

Jointly owned by NRG Energy, Google, and BrightSource Energy, the Ivanpah Solar Electric Generating System (ISEGS) sprawls across the California and Nevada border in the Mojave Desert. Ivanpah is a “hybrid solar plant”, relying on both solar power and power from natural gas. Ivanpah began operations in 2014 is still considered the largest concentrated solar plant (CSP) in the world, with facilities that stretch over 3,500 acres (development of CSP plants that will surpass the size of ISEGS are underway in Morocco and Dubai, but the entire Morocco plant won’t come online for a couple of years, and the Dubai plant not until well after that). The 377 to 400 megawatt ISEGS solar complex is revolutionizing the solar energy industry, proving that large scale renewable energy projects are not only possible, but can both thrive and surpass expectations.

With a complex including three CSP plants, ISEGS produces enough clean, renewable electricity to power 140,000 homes during peak hours, and almost double that amount during off peak hours. In fact, ISEGS produces double the amount of commercial solar thermal energy than any other plant in the United States.

ISEGS officially broke ground on October 27, 2010 and opened for business in February of 2014. Despite being one large complex, the project was actually broken down into three separate plants, each with their own 400-plus foot tower affixed with water filled receivers/ boilers. The specific technology used is known as Luz Power Tower 550, which was developed by BrightSource Energy with the goal of creating a unique take on traditional energy generation that harnessed and increased the power of the sun.

Ivanpah covers 3,500 acres, and each plant relies on solar receivers filled with water nestled atop the towers (as well as natural gas). By using 300,000 mirrors, known as heliostats, to increase the sun’s energy and reflect the light directly onto the solar receivers at strategic angles, the water in the receivers is heated to such high temperatures that it dissolves into steam. From here, the steam is then piped into a conventional turbine to generate electricity, which feeds into the power lines connected to the adjacent communities.

This large scale renewable energy project eliminates 450,000 tons of carbon dioxide emissions every year, the equivalent to removing 70,000 cars from the road.  And because the complex uses dry cooling to condense the steam, it consumes significantly less water than similar steam-powered plants. However, when it’s cloudy, or the sunshine is otherwise not readily available, the plant is able to run on natural gas, as well as the stored thermal energy from the solar concentrating power system.

Awarded Plant of the Year by POWER Magazine in 2014, the Ivanpah complex is proof that large-scale renewable energy projects are not only possible, but efficient as well. This massive complex was constructed in just 4 years, added jobs and funds to a somewhat dwindling economy, and is already dramatically reducing the amount of carbon emissions pumped into the atmosphere.

Please see:


COP21 – good news for the planet

 On the 12th of December, 2015, high-level representatives from 195 nations, including many presidents and prime ministers, agreed to try to hold warming “well below” 2 °C above pre-industrial temperatures. On April 22, at the UN in NYC, the agreement takes full effect (once nations representing a majority of the planet’s GHG emissions sign the agreement). Unfortunately, the truth is that, even if the agreement in Paris is carried out by every nation, and to the letter, global temperatures will still be on course to rise by around 2.7°C by the end of the century.

Luckily, the best news of the entire COP21 came on Day 1 with the announcement of the Breakthrough Energy Coalition ( The Breakthrough Energy Coalition is a group of more than 20 billionaires (including Bill Gates and Mark Zuckerberg {CEO of Facebook}) who have agreed to invest in innovative clean energy. The Coalition wouldn’t be able to fund and meet all of its goals without the most important international commitment by governments to invest in clean energy to date. Mission Innovation ( is a group of 20 countries including the U.S., Brazil, China, Japan, Germany, France, Saudi Arabia and South Korea, who have pledged to double government investment in clean energy innovation and to be transparent about its clean energy research and development efforts. In a statement from the Coalition, the importance of both groups is highlighted –

“THE WORLD NEEDS WIDELY AVAILABLE ENERGY that is reliable, affordable and does not produce carbon. The only way to accomplish that goal is by developing new tools to power the world. That innovation will result from a dramatically scaled up public research pipeline linked to truly patient, flexible investments committed to developing the technologies that will create a new energy mix. The Breakthrough Energy Coalition is working together with a growing group of visionary countries who are significantly increasing their public research pipeline through the Mission Innovation initiative to make that future a reality.”

Brazil was one of the last countries to join the ‘high ambition coalition’, while China and India were hold outs to this section of the pact. The ‘high ambition coalition’ are a group of countries, including most of the “Mission Innovation” countries and a group of the most vulnerable (smaller generally, and poorer) nations, that are looking towards a more ambitious goal of limiting global temperature rise to 1.5°C. China and India are the major emitters in the developing world, and were the last agree to the main pact, but not the high ambition goal, at COP21.

Below are some major resources for more information on the COP21:


COP21 Paris – breakdown of the event

coal plant

Stabilize greenhouse gasses

There are numerous ways that we can stabilize greenhouse gasses, thereby “stopping” climate change. Governments of 1st world and even developing nations must implement some of the following policies (and most might, at least implement some of the following, especially after the upcoming COP meeting of the UNFCCC in Paris). Clearly, the path to stabilize GHG emissions includes making it a priority for governments to financially invest in at least some of these solutions:


1. A carbon tax, or carbon cap-and-trade system, or both

2. Further investment in, and development of all forms of renewable energy including: wind, solar, geothermal and biomass/biofuel etc…

3. Carbon capture and storage

4. Widespread adoption of hybrids, plug-in hybrids and electric vehicles, as well as sustainable mass transportation using biofuel or electricity (bus systems, light rail etc…)

5. More use of, and development of smart grid infrastructure – smart meters, home energy management systems etc…

6. Energy, especially renewable energy, storage



This is certainly an incomplete list, so please feel free to add points.

Combined heat and power

Combined heat and power (cogeneration) – making the most of energy

Combined heat and power (CHP, also known as cogeneration) is the simultaneous production of power (electricity) and heat from: natural gas (dominantly), coal, oil, biomass, biogas and waste heat (recovery), among other sources. Waste heat can be heat from waste incineration, waste heat from power production and/ or industrial/ commercial/ even residential waste heat. Fuel sources vary from project to project, country to country.

For example, in Iceland, the dominant source for CHP is geothermal. Over half the energy use in Iceland, which has the highest energy use (per capita) of any nation in the world, is geothermal, and much of it CHP. This is energy production for electricity and heated water/ steam for fish farms, pools, etc… and also for geothermal district heating and space heating in general.


CHP can be seamlessly integrated in a number of energy technologies. Often, systems are developed exclusively for onsite generation of electrical and/ or mechanical power, in addition to HVAC and water heating. CHP is most often developed with a gas turbine and  a heat recovery unit or a steam boiler with a steam turbine. CHP exists in industrial and commercial buildings, institutional campuses, municipal facilities (district energy systems, wastewater treatment facilities, etc…) and is also implemented for residential properties.

CHP significantly reduces greenhouse gas emissions by 1/3 to ½ or more, and is significantly more efficient, requiring less fuel to produce a given energy output. CHP can produce electricity and thermal energy on site, avoiding the grid and avoiding energy losses that occur via standard transmission and distribution, as well as power outages. The high efficiency inherent in CHP saves consumers money on their utility bills, offering a reliable source of high-quality energy.



Community Solar

Community solar and net metering – pushing renewable energy forward

Community solar refers to energy generated by a solar farm that is invested in by a relatively small portion of the estimated 85% of residential customers who can’t have solar panels on their rooftops or property due to their roofs being physically unsuitable, because the roof/ property is often in shade by another building or trees, because they are renters, or for some other reason. The solar farms are constructed by individual developers, or a group of investors (the construction can also be done by the utlity itself), in select areas that are suitable for community solar, have a demand for the service, and can range from a few dozen panels to thousands. The customer invests in a few or more of the panels, receives credit for the power they consume at a fixed rate (usually fixed) per kilowatt-hour that is then deducted from their utility (electric) bills.

Net metering, on the other hand, is for residential customers who have PV systems on their rooftop/ property that may generate more electricity than the home uses when the sun’s out. The PV systems are connected to the grid via the owner’s service panel and meter. The owner of the PV system is credited when excess energy is generated than is needed for the home, i.e. times when the meter moves “backwards”. The customer then pays the “net” of the meter moving in both directions – forwards to measure power purchased (when the home demand is greater than the power generated by their PV panels), and backwards when power is returned to the grid. The net consumption is then charged on the utility bill.

Both community solar and net metering encourage power consumption in homes by means of solar energy. Both are great ideas for states in the US (where both of these ideas have found some success), and for countries all over the world. Both represent concepts that enable renewable energy to reach more of the public (illustrated more in the case of community solar) and make solar more desirable (highlighted in the case of net metering). Whether the purpose is to spread clean energy or to reap the financial benefits of the solar boom, both community solar and net metering are undeniably positive ideas.


Gasification Applications Chart

Gasification – syngas from fossil fuels and environmentally friendly versions

The creation of syngas (or synthetic natural gas) is a technology based on coal gasification for the majority of plants, although it can also be based on biomass or other, fossil, fuels. Since it is also usually based on a nonrenewable fossil fuel, and usually involves the emission of greenhouse gasses like CO2, it can’t be described as a “green” technology. However, when coal gasification is used in conjunction with carbon capture and storage (CCS), or a green technology like integrated gasification combined cycle (IGCC), or when syngas is created using biomass, the technology is certainly “greener” than burning a fossil fuel. IGCC is a fairly new technology that uses a gasifier in converting coal and biomass into syngas, and has come to be known as “clean coal”. Syngas plants use coal gasification for the most part, but to make the production of syngas greener, use of IGCC or biomass must be implemented.

Lignite, a brownish type of coal, is most often used as a source in the process of creating syngas. Gasification uses the coal, steam and oxygen to create syngas — mostly hydrogen and carbon monoxide. The syngas can then be burned directly to create energy used to generate electricity or heat homes and businesses, convert the syngas into “substitute natural gas”, or can be used to create products including methanol, nitrogen-based fertilizers and hydrogen for oil refining and transportation fuels. Coal gasification is sometimes called “clean coal” because it can create energy with less harm to the environment than traditional fossil fuel use.

A significantly more environmentally friendly version of gasification, other than coal use, is available in biomass. Biomass gasification uses a feedstock as in agricultural residues (like wheat and straw), energy crops (like switchgrass), forestry residues and urban wood waste (for example, from construction sites).

The leading region in the world for syngas production is Asia/ Australia, in particular China. China mostly uses coal for its syngas production, relying on their vast coal deposits, thus still producing significant quantities of greenhouse gas emissions. China is trying to rely more on domestic sources for gas and less on importing liquefied natural gas. A significant number of gasification plants are found in India, South Korea, Taiwan and Singapore.

The Africa/ Middle East region also produces a significant quantity of syngas, more than Europe. However, production of syngas in Europe uses a wider selection of feedstocks, technologies and products than other regions. The coal-based units primarily utilize IGCC technologies. There are petroleum, natural gas and biomass plants that produce either power or chemicals. A fairly new plant in Swindon, England illustrates the advancements that European nations are making with gasification. Methanization is used to transform gasified biomass into grid-quality syngas, the biosynthetic natural gas then providing power to the grid.

Most syngas production in North America lies within the United States. These plants include: natural gas facilities that primarily produce chemicals, coal and petroleum plants that produce either power, chemicals and fertilizers or syngas, including a couple of IGCC plants. In Canada, gasification is used to produce hydrogen and power to upgrade synthetic crude oil from the tar sands.


Cellulosic biofuel

Cellulosic biofuel – one fuel option

Ethanol is traditionally made from food crops like corn and sugarcane, but it can also be made from cellulosic feedstocks, non-food crops or inedible waste products. Examples of sources for cellulosic biofuel are crop residues, Miscanthus, switch grass, paper pulp, packaging, cardboard, sawdust, wood chips, rice hulls, corn stover and the byproducts of lawn and tree maintenance.

Technically, almost all plants have the lingocelluloses needed to produce ethanol from cellulosic material. Once glucose is freed from the cellulose using enzymes, fermentation produces ethanol, similar to how ethanol is traditionally produced from 1st generation biofuel sources. Lignin is also produced in the process, which can be burned as a carbon-neutral fuel for local processing plants, businesses and perhaps even homes.

There are tons of cellulose containing raw materials that could be used to produce ethanol that are simply thrown away each year in the U.S. alone. Examples of this are over 100 million dry tons of urban wood wastes and forest residues and over 150 million dry tons of corn stover and wheat straw. That material plus just a fraction of the other paper, wood and plant products that could be used to create ethanol instead of garbage would be enough to make the U.S. independent of foreign oil. This theme is true in other parts of the world as well.

Financial concerns stop cellulosic biofuel from really taking off and providing a consistent source of fuel. This type of ethanol production involves an additional step, the breakdown of the raw material into glucose with enzymes, which translates into a higher cost. However, the raw material is abundant, and the reduction of greenhouse gas emissions from cellulosic biofuel can be up to 90% compared to fossil fuel petroleum, significantly greater than those obtained from traditional 1st generation biofuels. Cellulosic raw material can be easily grown in land marginal for actual agriculture or simply be diverted from landfills, in order to make the production of cellulosic biofuel more cost-effective. Cost-effective processes, such as using inexpensive enzymes to break down the cellulose, are being researched and developed as well.


algae farm

Algae Farms – the Future of Biofuel

Most biofuel in the world today is sourced from 1st generation crops like corn, sugarcane, soybean or other crops from traditional sources. In reality, most current biofuel sources are inadequate to meet rising global demands. In addition, much of current biofuel is derived from food products, needed to address hunger from the global food crisis.

One solution to producing biofuel, especially ethanol, without using crops that are usually designated as food, is to use algae. Algae, especially microalgae, production is becoming more and more economically feasible. This is because of its exceptionally rapid growth rate. Algae grow 20–30 times faster than many food crops, contain up to 30 times more fuel potential (in the form of oil) than soybean or even palm oil, and algae farms can be located anywhere.

One great feature of algae that makes it ideal for biofuel production is that up to 60% of its mass is oil. Another is that algae requires CO2 to grow, so it essentially sequesters CO2 from the atmosphere as it grows. Algae reproduce quickly, needing only sunlight and water, are non-toxic and biodegradable. As algae grows, the oil is harvested for fuel while the remaining green mass by-product can be used in fish and oyster farms.


Algaculture has proven, based on current algae production technologies, that it can provide future global energy needs while being economically viable and sustainable. Algae production also creates useful co-products, such as bio-fertilizers. If the production of these products is made part of the goal of algae farms, biofuel production from algae will become more economically competitive sooner. Algae offers a great source for a more sustainable transportation fuel, but also offers a range of other benefits and co-products, such as carbon sequestration and fertilizer.