Tag: Cogeneration

The DOE Fuel Cells Technology Guide

A fuel cell uses the chemical energy of hydrogen or another fuel to cleanly and efficiently produce electricity. If hydrogen is the fuel, electricity, water, and heat are the only products. Fuel cells are unique in terms of the variety of their potential applications; they can provide power for systems as large as a utility power station and as small as a laptop computer.

WHY STUDY FUEL CELLS

Fuel cells can be used in a wide range of applications, including transportation, material handling, stationary, portable, and emergency backup power applications. Fuel cells have several benefits over conventional combustion-based technologies currently used in many power plants and passenger vehicles. Fuel cells can operate at higher efficiencies than combustion engines, and can convert the chemical energy in the fuel to electrical energy with efficiencies of up to 60%. Fuel cells have lower emissions than combustion engines. Hydrogen fuel cells emit only water, so there are no carbon dioxide emissions and no air pollutants that create smog and cause health problems at the point of operation. Also, fuel cells are quiet during operation as they have fewer moving parts.

HOW FUEL CELLS WORK

Fuel cells work like batteries, but they do not run down or need recharging. They produce electricity and heat as long as fuel is supplied. A fuel cell consists of two electrodes—a negative electrode (or anode) and a positive electrode (or cathode)—sandwiched around an electrolyte. A fuel, such as hydrogen, is fed to the anode, and air is fed to the cathode. In a hydrogen fuel cell, a catalyst at the anode separates hydrogen molecules into protons and electrons, which take different paths to the cathode. The electrons go through an external circuit, creating a flow of electricity. The protons migrate through the electrolyte to the cathode, where they unite with oxygen and the electrons to produce water and heat. Learn more about:

View the Fuel Cell Technologies Office’s fuel cell animation to see how a fuel cell operates.

RESEARCH AND DEVELOPMENT GOALS

The U.S. Department of Energy (DOE) is working closely with its national laboratories, universities, and industry partners to overcome critical technical barriers to fuel cell commercialization. Cost, performance, and durability are still key challenges in the fuel cell industry. View related links that provide details about DOE-funded fuel cell activities.

  • Cost—Platinum represents one of the largest cost components of a fuel cell, so much of the R&D focuses on approaches that will increase activity and utilization of current platinum group metal (PGM) and PGM-alloy catalysts, as well as non-PGM catalyst approaches for long-term applications.
  • Performance—To improve fuel cell performance, R&D focuses on developing ion-exchange membrane electrolytes with enhanced efficiency and durability at reduced cost; improving membrane electrode assemblies (MEAs) through integration of state-of-the-art MEA components; developing transport models and in-situ and ex-situ experiments to provide data for model validation; identifying degradation mechanisms and developing approaches to mitigate their effects; and maintaining core activities on components, sub-systems, and systems specifically tailored for stationary and portable power applications.
  • Durability—A key performance factor is durability, in terms of a fuel cell system lifetime that will meet application expectations. DOE durability targets for stationary and transportation fuel cells are 40,000 hours and 5,000 hours, respectively, under realistic operating conditions. In the most demanding applications, realistic operating conditions include impurities in the fuel and air, starting and stopping, freezing and thawing, and humidity and load cycles that result in stresses on the chemical and mechanical stability of the fuel cell system materials and components. R&D focuses on understanding the fuel cell degradation mechanisms and developing materials and strategies that will mitigate them.

Combined Heat & Power (CHP) Basics

Combined Heat and Power CHP

Energy costs can be reduced by as much as 50% with an onsite CHP system.

The concept of combined heat and power or cogeneration is simple: Why use two fuels when you can use one? Combined heat and power is the simultaneous production of electrical and thermal energy from a single fuel source. It is sometimes referred to as cogen, waste heat recovery, or C.H.P. All CHP applications involve recovering heat that would otherwise be wasted while generating electricity. The captured heat is utilized as useful thermal energy instead of being allowed to dissipate in the surrounding environment.

cogen-fuel_01

Separate production of electricity and heat efficiency: (36+80)/200 = 58%

cogen-fuel_03

Cogeneration efficiency: (30+50)/100 = 85%

The U.S. Environmental Protection Agency (EPA) views cogeneration as a “proven, effective and underutilized near-term energy solution to help the United States enhance energy efficiency, improve environmental quality, promote economic growth and maintain a robust energy infrastructure.”

In the U.S., there are over 3,700 industrial and commercial facilities using onsite CHP which make up the United States’ 8% of total generating capacity. The Obama Administration is supporting a national goal to achieve a 50% increase in CHP generating capacity by the end of the year 2020. Yet even if the U.S. achieves this goal, the nation will still be lagging far behind countries such as Denmark, Finland and the Netherlands, which already boast a 30% CHP generating capacity.

Cogeneration is often used in large industrial installations that require a constant stream of electricity and heat to operate. However, CHP can also be used in hotels, hospitals, nursing homes and any other type of facility that needs both electricity and heating & cooling.

What does a CHP system look like?

CHP systems can be as small as a typical office desk, or as large as an entire power plant. Though a combined heat and power  system is sometimes difficult to explain, anyone who has ever been in a car in cold weather has experienced cogeneration first-hand. A car’s engine essentially becomes a CHP plant when the waste heat from the engine is captured and used to help warm the vehicle’s interior; concurrent with the gas powering the drivetrain and making electricity through the alternator.

The most common CHP system configurations include heat recovery units used in conjunction with gas turbines, reciprocating internal combustion engines, or steam boilers with steam turbines. Reciprocating engine CHP systems are suitable for use in places such as universities, hospitals, water treatment facilities, commercial and residential buildings, with consistently high demand for electricity, heating & cooling and hot water.

A steam turbine CHP system uses waste heat for electricity generation, mechanical drives, district heating and cooling systems or combined cycle power plants. Steam turbine CHP systems are often used in paper mills, chemical plants and other industrial applications where there is a variety of waste fuels available.

CHP Benefits

Kolanowski writes, “…A reciprocating engine CHP system designed to produce 120 kilowatts of electricity and 5.62 therms of thermal energy (hot water) has a fuel-usage efficiency of more than 90%…

…A customer buying electricity from a central station utility AND heating water in his on-site water heaters will purchase 817,666 Btu’s more fuel to gain the same useful energy than if he were cogenerating on site. And that is for every hour he needs that energy! A facility open seven days a week for 16 hours a day will buy 47,751 more therms of energy per year than the same facility using on-site cogeneration. At an average street cost of $0.75 per therm, that’s $35,813 more dollars spent just in fuel costs alone… “

…the amortization of on-site cogeneration ( i.e. the time to recoup the capital costs of the system), is an average of three years or less, even after accounting for operating and maintenance costs of the system.”

In addition to the improvements to efficiency, cost-savings and lower greenhouse gas emissions, one of the biggest advantages of CHP is the enhanced reliability benefit. A CHP system can be set up to provide on-site electricity generation and thermal heat to a facility, even in the event of a power grid failure. CHP can reduce the risk of brownouts or blackouts interfering with sensitive industrial equipment.

Obtaining a CHP System

Determining which type of combined heat and power system would be a suitable fit is easy. To begin, an energy consultant simply needs to assess the energy needs of the facility. This involves rules and regulations designed to discourage decentralized power generation, including CHP and solar. Cogeneration options include purchase, lease, and a Power Purchase Agreement (PPA) where the customer only buys the energy at a discount with no investment.

To help navigate through all the complexities of getting a combined heat and power system installed in your facility, EE Reports offers comprehensive cogeneration consultation services and project oversight.

Rapid demand growth predicted for distributed generation technologies

Investment in on-site power technologies is projected to reach over $155 billion through 2023, up from $1.8 billion today, new analysis has found.

According to Navigant Research’s latest microgrid study, the global market for ‘microgrid enabling technologies’ such as diesel generators, natural gas-fueled generators, fuel cells, combined heat and power (CHP), solar photovoltaics (PV), distributed wind power, micro-hydropower, biomass, smart islanding inverters and energy storage will see rapid demand growth over the next several years.

‘Dramatic change is occurring in the microgrid market, as the economic value that these systems bring to the overall power grid becomes more and more apparent,’ said Peter Asmus, Navigant’s principal research analyst and report lead. ‘We expect the technologies that enable these systems to play key roles in the expansion of the microgrid sector to encompass additional technologies and services related to smart buildings, demand response, distribution and substation automation, and smart meters.’

According to the report, while Europe currently leads the market for microgrid-enabling distributed generation technology with a 40% market share and $714.2 million in revenue, by 2023 North America will take the lead, pulling in $4.9 billion, up from around $600 million in 2014.

Among the technologies, energy storage is projected to represent the single largest investment category among microgrid-enabling options by 2023.

via Rapid demand growth predicted for distributed generation technologies – Cogeneration & On-Site Power Production.