Cogeneration

Cogeneration combines heat and electricity. During electricity production, we recover thermal energy using a single fuel source.

The cogeneration process (CHP) provides hot water, chilled water, heat, or air, as well as a reliable source of electricity by recovering and recycling excess heat that is normally lost during electricity production. Furthermore, being energy efficient, CHP is more economical and environmentally friendly than traditional energy generation methods.

Advantages of CHP systems

In short, there are three main advantages of CHP systems:

1. CHP systems can produce 2 to 3 times more usable energy from the same amount of fuel than separate dedicated systems
2. CHP systems generate financial savings through improved return on investment and reduced energy costs
3. CHP systems produce almost 80% less carbon dioxide per unit of energy consumed in the production cycle compared to separate dedicated systems

Differences between generating electricity from a generator and CHP systems

Briefly speaking, what is the difference between traditional electricity generation from a generator and CHP systems?

1. Traditional generators use liquid or gaseous fuels to generate electricity, but approximately 60% of this energy is lost in the production, transfer and distribution process, which means that the efficiency of such a system is only about 40%
2. Cogeneration systems also use fuels, though in this case, gas, to produce electricity. However, in this case, approximately 94% of the fuel used can be used to produce a usable form of energy. The unit converts 50% of its power into thermal energy and the remaining 44% into electrical energy. Only 6% is lost in the conversion process.

There are also additional benefits to CHP systems. Combined cooling, heat, and power (CCHP), also known as trigeneration, is an extension of cogeneration. In this process, the heat generated from cogeneration is used to generate cooling energy, which in turn can produce chilled water for use in air conditioning or refrigeration. Quadruple generation is also an extension of CHP. In addition to heating or cooling, this type of generation also utilizes carbon dioxide from exhaust gases for use in greenhouses and the food industry

Every CHP system relies on the same essential components used to recover heat from the generator. The following components are required in every cogeneration system (or higher):

1. Heat exchangers transfer thermal energy from fluids or gases to other systems. Plate, tubular, or condenser heat exchangers can be used. They transfer heat produced by the generator to the customer's industrial processes using separate circuits.
2. Chillers are a key component of CHP. They are most often used in the heat discharge process, as the heat produced by the generator is not used for cogeneration.
3. Pumps, valves, and piping—the systems that transfer heat between circuits—are typically installed upstream of the chiller (on the radiator side).
4. The CHP electronic control system, or SCADA system, communicates with the generator controller, allowing customers to collect and process information from the system. It allows them to operate and control their industrial process via an HMI (human/machine interface).
5. The grid synchronization system, also known as parallel operation, ensures a safe and efficient connection to the grid. It allows for synchronization of four basic current parameters with the grid: voltage, frequency, phasing, and phase rotation direction, which in turn allows for the transmission of current to the grid.

What benefits can a CHP system bring to individual customers?

The needs of individual customers can vary, as can their areas of operation. For example, industrial customers, such as factories, chemical plants, mills, and so on, can utilize steam for industrial processes. Business customers, including office buildings, greenhouses, data centers, hospitals, hotels, swimming pools, and many others, can utilize the additional energy from CHP to heat water. This energy can then be used for sanitary purposes, building heating, or, in the case of greenhouses, for carbon dioxide recovery to fertilize crops.  Customers from the broadly understood public domain can also use CHP systems to heat or cool their buildings or produce domestic hot water.

CHP systems, which produce both electricity and heat from the same fuel source, can offer energy savings of around 35% for a wide range of customers and facilities. However, it's important to remember that CHP systems are most efficient when operated for at least 5,000 hours per year.