Gas power plants cost 1 kilowatt. Generator profitability: how much does one kW cost. Preliminary calculation of lease payments

2006-03-20

Changes in the management of the Russian economy have caused an increase in interest in small-scale energy projects. It became clear to the consumer that during the period while RAO "UES of Russia" is busy with its restructuring, and for a long time after that, there is no need to hope for a reliable and cheap power supply from large-scale energy, especially for new facilities. The cost of building your own power plant in Moscow and the Moscow region turns out to be the same as the cost of connecting to the Mosenergo system.

Large energy consumers have sufficient funds to hire qualified experts to assess the cost of building their own energy facilities or to choose options for cooperation with energy systems on joint participation in the reconstruction of generating and grid facilities.

But specialists and managers of small businesses and municipalities need to be guided by themselves in the choice of energy efficient projects.

Technical literature and popular publications are littered with various recommendations for the use of small and alternative energy, incl. on the use of wind, solar, micro-hydroelectric power plants, small thermal power plants using biofuels and all sorts of rubbish. Undoubtedly, all suitable power plant options should be considered out of a million ...

However, recommendations based on the proven experience of Western countries are often economically unjustified in Russia, and the payback period for conventional CHP projects in Russia is sometimes twice or less than in the United States. In this article, another attempt is made to determine the "zones" of application of different options for small CHP in Russia.

The main difference between small energy

Energy supply from large power plants presupposes the presence of electrical and heating networks through which energy is transmitted to a large number of consumers divided by categories of reliability of consumption, consumption volumes, social status and, accordingly, tariffs. The need to build and operate networks doubles or triples the cost of energy received by end users both in our country and abroad.

A small CHPP is being built for one or a group of consumers, united into a local network. Since the length of the networks is minimal for an individual small consumer, in the further analysis we will consider only the cost of generation and modes of energy use for the consumer himself.

Big energy as a landmark

When considering projects for the construction of small thermal power plants, power engineering specialists and specialists of enterprises are guided by the indicators achieved in the large power industry. In the large power industry, more and more complex power generation schemes are used. The efficiency of power plants is also growing, mainly due to the use and complication of power plants with combined cycle plants.

If the efficiency of steam turbine power plants for 40 years has frozen at around 42%, then the efficiency of power plants with a complex cycle, including electric generators with gas turbine and steam turbine drives, in 1993 had a "parade" efficiency = 51.5%, and three years ago, i.e. e. in 2003, the efficiency of such installations (in the West) increased to 56.5%, i.e. grew by 0.5% per year. And the prospects for increasing the efficiency of conventional "thermal" power engineering are still great.

Differences in small energy

For obvious reasons, we exclude nuclear power plants and solar power plants (SES) from consideration. Of course, only a lazy summer resident in Russia did not install a solar water heater for the shower. As for solar power plants, in our country and in the North Caucasus there is less sun than in California, and in California the cost of "green energy" from a solar power plant is twice as high as from traditional power plants.

It is expensive to build a good coal-fired power plant with a capacity of less than 10 MW. But the Danes are building boilers and thermal power plants that burn wood waste, and even straw. But in Russia, the wheat yield is lower and it is more difficult to collect straw (A.M. Mastepanov). Harder to collect and burn city trash. Such projects should be large enough. We will not "delve" into hydrogen energy either.

New-fashioned hydrogen energy in terms of efficiency will not be able to keep up with conventional energy. Yes, small CHP plants on hydrogen with direct conversion of hydrogen energy in electrochemical generators must be reliable (there are no high-temperature surfaces and a lot of rotating units - turbines, generators, pumps), in fact, environmentally friendly, because the catalytic oxidation of hydrogen produces only H 2 O emissions.

However, in terms of cost and efficiency as a whole, hydrogen power engineering is not yet "close" to conventional power engineering. The Americans themselves finally wrote about this frankly two years ago. And besides, in a conventional gas turbine plant (GTU), in which natural gas is burned (natural gas and air are supplied to the burner through compressors under pressure), and high-temperature gases spin up the power turbine, compressor and electric generator.

Air is supplied to the gas turbine in excess: it works as a "working fluid" in the turbine, and part of it is simply used to cool the walls of the burner and turbine blades. In the last two decades, gas turbine plants have been built in which air was partially replaced by water or steam. At the same time, the efficiency of the gas turbine plant increased by one and a half times, the specific power of the unit increased by one and a half to two times (with the same volumes).

With modern technologies in such cycles, an electrical efficiency of 64% is attainable (such an efficiency is not planned in hydrogen power engineering ...) In fact, a complex steam-gas cycle is realized in one turbine unit! In addition, harmful emissions of nitrogen oxides (NO X) are significantly reduced. And if you supply oxygen to the turbine, not air? Then nitrogen will not enter the combustion chamber and there will be no nitrogen oxides.

Oxygen production is becoming cheaper and cheaper due to the development of membrane technologies. According to information leaked to the Internet, such a project is under development in the United States, and it is possible that by the end of 2006 or early 2007 there will be test results. Well, just a "balm for the soul" for environmentalists! These achievements are again not for us! Neither RAO UES of Russia, nor the state finances such "breakthrough" projects. In small-scale power engineering, it is impractical to consider the possibility of using complex schemes of combined cycles of CCGT for electricity generation. We will restrict ourselves to simple solutions.

Small CHPPs for Russia

It is more profitable to generate both electricity and heat at a CHP plant than separately generating heat at a boiler house and separately generating electricity at a power plant. The fuel consumption gain is 30%! Everyone needs a CHP! Thermal power plants that supply heat and electricity generate about 60% of all electricity in Russia. Russia is the coldest of all the great powers.

But here's the difference: in principle, we need more heat than other countries! And with such a requirement, super-high electrical efficiency is not needed, i.e. it is possible to use simpler and cheaper power plants. In many industries, year-round heat costs are higher than electricity costs. The population needs heat in summer only for hot water supply, and this is only 15-20% of the winter consumption.

In shopping centers and large office buildings, cooling (air conditioning) is also needed in Russia in the summer. And in these cases, more electricity is needed, i.e. the electrical efficiency of the CHP plant should be higher. What is the choice of power generating plants for a small CHP (or TPP)?

Steam turbine units - PTU (any fuel for the boiler)

Russian steam turbine installations. The smallest with good efficiency, but at least 500 kW in power at a cost slightly higher than $ 300 / kW. (there are others, but with low efficiency and unknown reliability);
American steam turbine units: 50 and 150 kW at a cost of $ 450-500 / kW. Do not forget to also build a steam boiler at a cost of approximately $ 50 / kW with all the personal belongings (if you do not have a steam boiler).

Conventional gas turbine plants - GTU (fuel: gas or diesel)

To obtain heat, waste heat boilers are needed (in terms of unit cost, they are comparable to steam boilers).

Russian gas turbine units with a capacity of 2500 kW and more, the cost is approximately $ 600 / kW. Efficiency = 24% and more with increasing power;
Ukrainian gas turbines with the same performance (there is also one with water injection into the turbine to increase power and efficiency);
others, but more expensive.

It is possible to use a gas turbine with a lower power, but at the same time reliability decreases (gearboxes are used) and the specific cost of 1 kW of installed power sharply increases.

Unusual gas turbines

Sold in Russia high-speed gas turbine units(made in the USA and Europe). Their capacities: 30; 70; 100 and 200 kW. With low efficiency = 17-22%. Expensive, more than 1000 $ / kW (!), But very good for distant "points" because the lungs ... High-frequency noise is easily muffled! Piston Driven Power Generation Units(on gasoline, diesel fuel and natural gas). In terms of power from several kW to 6000 kW in one unit or more. In terms of efficiency (up to 43%), they exceed GTU and STU in all power ranges. In terms of maneuverability and independence from weather conditions, they are better than turbines. And the service life of piston units is two to three times higher than that of turbines. The unit cost depends on the power of the units. Gas reciprocating power generating units (running on gas) are significantly higher than diesel engines.

alternative energy

From alternative energy, we have a choice of hydroelectric power plants (HPP) and wind power plants (WPP).

Small hydroelectric power plants

There are excellent Russian hydroelectric generators. With a capacity of 1-5 MW, the cost of equipment is about $ 300 / kW. But don't forget the cost of constructing a dam, building, etc. There are sleeve and floating power plants. The cost of this equipment is more expensive. Most of the rivers are flat and it is a problem to build a dam of considerable height ... And in winter, rivers in Russia freeze over. And there is a way out. An underwater hydroelectric power station can be built on a large river. To do this, you need to install on the barge hydroelectric generators of the type of wind turbines. Bring the barge along the river to the village, connect it with a cable to the shore and ... flood it so that the upper edge of the hydrogenerator blade would not reach the bottom in winter. This expensive solution may turn out to be acceptable for some northern village, where the cost of fuel is five times higher than in Moscow.

Wind power units have always been referred to as small-scale power generation. But over the past 10 years, the capacity of individual wind turbines has grown from 350-500 to 3500 kW. At the same time, their cost decreased from $ 1,500 to $ 900 / kW. Onshore and offshore wind farms with dozens of units with an assembly capacity of over 40 MW have already been built. This is in Denmark and Germany.

Back in 1992, in Kalmykia, we supplied a 1000 kW unit. But it did not work - either because the bearings burned out, or because the USSR was gone. The Danes were ready to sell us a second-hand wind farm with a capacity of 350 kW for "pennies" (three to four times cheaper with a six-year warranty, but bad luck - the wind speed in Denmark (almost an island) from all directions is about 8 m / s, and on the Russian plains, only 3-5 m / s.At such speeds, the developed power will be in ( 8 / 5 ) 3 = 4.7 times less!

And when this cheapness will pay off! Of course, in our North the wind speed is more than 8 m / s, but will the Danish plastic blades (designed for year-round freezing temperatures) withstand our frosts of -50 ° C? And what about the oil in the gearbox? And the electronics? It happens that there is no wind either. Then you need to combine a wind farm with a diesel power plant. One of the options proposed by Russian engineers is to use most of the wind farm energy for heating.

Indeed, the greater the wind in winter, the more heat is “blown out” of the house, but the more (in a cubic degree!) The wind turbine gives energy. Moreover, it is possible not to stabilize the frequency and voltage, but to supply such "non-GOST" electricity directly to a water boiler or simply to electric heaters. The construction of the generator will be much cheaper. No gear needed.

It is possible to supply aircraft-type blades with "no rotation speed limitation" even in a storm. But this is a special task. For those places where fuel is delivered by the Northern Sea Route. At present, different types of low-speed wind farms are being invented in Russia. But the cost of small-scale production of wind farms is and will be higher than in Denmark, where the national wind farm industry and their serial production have been created. This is a Danish "trick" and Danish pride.

However, the Danish government stopped subsidizing the construction of wind farm in 2002, because in reality the cost of electricity from a wind farm was much higher than electricity from conventional thermal energy. Look at the picture how electricity is expensive in Denmark.

Comparison of the costs of various power plants

Comparison of the costs of various power plants reduced to 1 kW has been published infrequently in the technical literature. Such an article was published 20 years ago by E.M. Perminov and a few years ago a similar comparison was made by P.P. Handless. These are specialists in non-traditional energy well-known in Russia. Over the past decades, the cost of conventional CHP and nuclear power plants has increased, while the cost of solar and wind power plants has decreased significantly. Below is a comparison of costs for thermal power plants.

Conclusion

In addition to Mosenergo, Moscow is designing and building new combined-cycle CHPPs (Moscow-City and others, 160-200 MW), gas turbine power units (domestic power units of 6-10 MW and more) are installed at district heating stations and boiler houses, t .e. boiler houses are being converted into CHPPs. New shopping malls around Moscow and in Moscow are acquiring their own "trigeneration" power plants (electricity + heat + cold) with a capacity of 4-6 MW using foreign-made gas piston power units.

Questions are periodically raised about the construction of new waste processing plants and thermal power plants with waste incineration in Moscow, Ryazan and other cities. In previous years, several foreign-made wind power plants were supplied for foreign grants on the coast near St. Petersburg and near Kaliningrad. But there are no happy reports on solar power plants within Russia.

For the foreseeable future, the conventional electric power industry based on gas CHPPs in Russia will remain a very profitable business, given that the cost of electricity and heat in a number of regions of Russia has approached world prices, and the cost of natural gas is still five times lower than in Europe and the foreseeable future will always be half the price (due to the difference in shipping costs).

You need to build your own CHP now if there is gas. In other cases, consider the options. Graphs and tables are taken from the literature below. The rest of the figures in the assessments are given from the memory of the author from his own assessments and publications of Russian and foreign experts.

Don’t ignore network costs. Michael Brown. Director ofWADE and Editor of COSPP. Cogeneration & On-Site Power Production. July-august 2005.
Reforming district heating in European transition countries. “Restructuring district heating in Europe’s transition economies”, COSPP, July-August 2005, Sabine Froning and Norela Constantinescu.
www.Eia.doe.com.

It should be said right away that generator electricity is more expensive than power supply from the external network... But electrical appliances have become so deeply embedded in our everyday life that we cannot give up comfort and convenience.

A cottage owner who is unlikely to be puzzled by the cost of electricity. The situation is the same with picnic generators - there simply are no other options.

This is another matter if you plan to use the generator set on a permanent basis. Electricity costs simply need to be considered by business owners in order not to burn out. Sometimes it's cheaper to connect to central networks.

Let's say you have a generator with a nominal power of 5.5 kW and a cost of 35 thousand rubles. Average service life is 5000 hours. Let's take the cost of a liter of fuel for 40 rubles. When calculating 1 kW / h, it is important to take into account the generator load, as it will affect the final value.

First of all, let's take into account the cost of purchasing the generator itself - we divide its cost by engine hours. 35000/5000 = 7 rubles / hour.

Then calculate the cost of 1 kW at:

100% load: 2.5 l / hour * 40 rubles / 5.5 kW = 18.18 rubles. Taking into account the cost of the generator, the total the cost of kW / hour will be 18.18 + 7 = 25.18 rubles.

50% load: 1.8 l / hour * 40 rubles / 2.75 kW = 26.18 rubles. Taking into account the cost of the generator, the total the cost of kW / hour will turn out to be 33.18 rubles.

If used consistently, maintenance costs should be included in the expense. Change of oil, filters, spark plugs and more. Therefore, estimate the annual maintenance costs of the generator and include them in the kW cost.

Summarize

The cost of 1 kW of electricity from a generator set is higher than from central networks. If the generator is planned to be used as an additional or backup source - you don't have to think about it.

This publication from the series “They are asking us” is devoted to the issue of assessing the feasibility of investing in our own generation.

In our practice, following the requests of our clients, we have developed two approaches to addressing this issue. The first comes down to calculating the cost of one kW of electricity produced. The second is to assess the energy balance of an enterprise when a new element is introduced into it - a gas-piston power plant.

In this article, we will focus on the first option for assessing the feasibility of investing in our own generation and gas-piston thermal power plant.

Below is the subject of the payback calculation. Let's consider the order of its preparation in more detail.

CALCULATION OF RETURN OF THE ENERGY COMPLEX GPU type ETW 1125 EG TCG 2020 V12K
Technical block
Euro rate		80,00
Installation cost	Euro	644 050,00
Installation cost	rub.	51 524 000
Rated power of the installation	kw	1 125
Number of installations	PCS.	1
Complex cost	rub.	51 524 000
Nominal capacity of the complex	kw	1 125
Complex operating time per year	engine hours	%	100	75	kw	1 125	845	562
Specific fuel consumption	kWh / kWh	2,37	2,45	2,56
Gas consumption	m3 / h	267	207	144
Heat dissipation of the coolant	kw	587	446	306
Heat transfer in the NT-circuit	kw	103	70	42
Exhaust heat dissipation	kw	685	570	431
Total heat dissipation	Gcal	1,09	0,86	0,62
Service cost data for 64,000 hours, including overhaul
Spare parts cost for 64,000 hours	rub.	52 311 776
Service cost for 64,000 hours	rub.	2 563 200
The cost of oil for waste for 64,000 hours	rub.	4 336 960
Oil change cost for 64,000 hours	rub.	1 712 160
Cooling cost liquids for 64,000 hours	rub.	124 320
Service cost for 64,000 hours	rub.	61 048 416
Service cost per hour	rub.	971
Economic block
The cost of purchased electricity	rub / kWh	3,60
Cost of purchased gas	rub / m3	3,72
Cost of production of a boiler house 1 gcal	RUB / Gcal	1 200
Heat consumption	%	40%
Gas consumption by the whole complex per hour	m3 / hour	267	207	144
Cost of consumed gas per hour	rub.	992	770	535
The cost of maintenance of the complex per hour	rub.	971
Maintenance costs of the complex per year	rub.	16 486 903	14 624 522	12 651 117
The cost of electricity being replaced	RUB / h	4 050	3 042	2 023
The cost of replaced heat energy	rub.	1 305	1 031	740
Total cost of replaced energy per year, taking into account incomplete heat consumption	rub.	38 406 413	29 017 269	19 479 982
Financial result from the use of the complex per year	rub.	21 919 510	14 392 747	6 828 865
Cost of produced kW of electricity excluding heat generation	rub.	1,73	2,06	2,68
Payback of the project	months	28	43	91

The maximum theoretical load of mini-thermal power plants cannot be equal to 100%. There are scheduled maintenance stops. Stops due to failures are also possible. Therefore, we limit the maximum number of operating hours per year to 8400 hours (96%).

For each gas piston engine, the manufacturer in the technical data indicates its parameters at 100%, 75% and 50% of the rated power. The electrical efficiency of the gas generator set changes depending on the load. The lower the load, the relatively more heat is produced and the less electricity is produced. We recommend that the calculation be carried out for all three values, this will give you the opportunity to get more realistic results.

Constants are entered into the first "technical block". For example, at 100% capacity, our gas-piston power plant will produce 1125 kW of electrical energy and 1.09 Gcal of heat, while consuming 267 m³ of gas per hour.

In the next block, we determine the cost of servicing our gas piston installation. To do this, we add up the costs of scheduled maintenance services, consumables, oil for replacement, oil for waste, antifreeze. We divide the resulting amount by the engine operating time before overhaul. For MWM engines, this is 64,000 hours. In our example, the cost of service per one engine hour is 971.00 rubles.

In the economic block, we enter the cost of gas in order to calculate the cost of gas consumption by a gas piston power plant. The cost of purchased electricity in order to assess the effect of own electricity generation. Similarly, the cost of heat produced by gcal for assessing the contribution from own cogeneration.

In our example, we also assume that the consumer does not need heat all year round, but only during the heating season (40%). Of course, the optimal case is when an enterprise needs heat energy for technological needs all year round, and we can completely utilize all the heat produced by the mini-thermal power plant.

Knowing how much we produce electricity and heat per year, as well as how much it would cost us to purchase them, we end up with the total cost of replaced energy per year. This is our revenue side. In our example, for 100% load, it will be 38,406,413.00 rubles.