Having lived one summer with a pair of solar panels and not waiting for the connection to the power grid, it was necessary to solve the problem of electricity supply for the next year. Winter was ahead and it was time to study the methods of autonomous power supply, and also choose what would be better: your own solar power plant, a wind generator or a compact hydroelectric power plant…
The first option was to acquire its own hydroelectric power plant. Quiet work, own pond and fishing - all this looks great until you plunge into theory. To extract energy, you must have either a decent elevation difference or a high flow rate. There is neither the first nor the second at our latitudes, so this option was swept aside immediately. It is worth noting that ready-made sets of mini hydroelectric power plants are produced in Russia.
The second and most attractive option was a windmill. “How?” I thought. “Because the wind is always there. And the beautiful blades will spin slowly and romantically.” The deeper I got into the theory of wind energy and read user reviews, the more my hair moved. Over time, I realized that it was impossible to live on one wind generator, if only because I do not live in the edge of the steppes and not on the sea or ocean, where there are constant winds. In addition, if there are forests around, or at least forest belts, this significantly affects the speed and strength of the wind, and hence, energy production. Having also studied the market for wind power plants, I found out that Russia has its own manufacturers of windmills, but there were problems with the guarantee, so I turned my eyes towards China, where mass production of such devices was launched. Based on the needs for energy consumption, I would like to have up to two kilowatts of power at the peak. As it turned out, such a windmill could produce even more, but then I looked at the graph.
It turns out that 2 kW of energy can be obtained with a wind speed of 9 m/s. The question arose, what kind of winds blow in my region? I started digging and saw that NASA had more data and was easier to get. In general, the wind map for the Russian Federation looks like this:
That is, if you put a windmill on a mast 10 meters high, you can count on an average annual wind of 4 meters per second. And this despite the fact that the blades sometimes move off only with gusty winds up to 5 m / s, and then the blades rotate even with a smaller wind. But the production starts at 2.5-3 m/s, and the energy inflow with such a wind will be only 200-300 W/h.
After reading a few more experienced people, I realized that you either need to live on a hill or raise the mast with a wind generator by 15 meters to get more wind. It must be remembered that the windmill requires periodic maintenance (at least once every two years) and in case of repair it will need to be lowered somehow.
And now let's estimate the accounting of such a windmill. We will take into account only the cost of the wind turbine itself, a special controller for it and the mast. Batteries are not considered, as they will be needed on a stand-alone basis, regardless of the source of energy. I will quote prices finished devices in Russia. It may be objected to me that in the same way you can buy pipes, weld them and make a mast yourself or order a windmill from China. As my practice has shown at the stage of creating solar panels, the economic feasibility of these actions is available only if you have extensive experience in self-assembly.
Wind power set (prices at the beginning of March 2015):
1. Windmill LOW WIND 48 2.5, 2.5 kW 48V with controller - 131880 r
2. Mast 15 m for wind turbine SWG-E - 32500 r
Total for the set: 164,380 rubles.
Kinda not very budget friendly. With this money you can buy a generator of about 6 kW and 7300 liters of AI-92 gasoline at a price of 32 rubles per liter. At a flow rate of 2.3 liters per hour, the generator will work 3175 hours or 132 days without stopping. It is clear that it is necessary to carry out maintenance on the generator and it will not work around the clock, but only at times of high loads or to charge batteries, but I considered that the wind generator is expensive for me.
Pros of wind energy: Cool, unusual, attracts attention. The worse the weather, the stronger the wind, which means more energy. There are exceptions - with a hurricane wind, to prevent failure, it is blocked.
Cons: high initial investment, large guy space for the mast (it is possible to install the mast without guys, but requires better foundation and the design is somewhat more expensive), wind dependence, noise
Let's turn to solar energy. The advantages are immediately noticeable: the absence of any sound vibrations, the possibility of a gradual purchase of modules and a step-by-step increase in power.
The cons are a little less obvious: you need a sufficient area with constant lighting, without a shadow. Weather dependence. Seasonality, since in winter the output drops by a multiple, relative to summer.
I switched to the side of the sun and started buying modules. Having studied more than one forum and studied the prices in Russian online stores, I decided to save money and turn to foreign sellers. The question of guarantee and reliability was raised, so I chose European suppliers of Chinese panels. At that time, they had a rather interesting offer when buying two 100 W batteries at once. Even with delivery, the cost was about 7 thousand rubles apiece. So I got 4 batteries and started looking towards controllers. It became clear that the efficiency of generation can only be increased with the help of an MPPT controller. Having studied the market, I ordered an EPSolar Tracer 3215RN controller via Ebay. It belongs to budget models, but it allows you to connect up to 150V to the input and withstand currents up to 30 A. With 12V batteries, it is able to digest up to 390 W of power, that is, my batteries were just right. And if you raise the voltage to 24V, then the digestible power doubles. That is, the controller, as they say, "for growth." In addition to my battery, I added another 190 Ah.
It became clear that the energy received must be spent, and Chinese inverters were not suitable for this at all. The idea came to get an inverter with a pure sine wave. This pleasure is expensive, but after studying several options, including Russian ones, I decided to take a Chinese device under a European name. This inverter is capable of delivering 1500 W to consumers for a long time, at a peak of up to 3000 W. That is, such an inverter will easily start all household electrical appliances with motors, as well as power tools. In autonomy, such a parameter as idle current is very important. IN this device this parameter was from 600 to 1000 mA, which is not very good, but tolerable, since the work was usually carried out under load and during daylight hours, the conversion losses were more than compensated.
I must say that before buying, I even found an OEM manufacturer of these inverters in China and contacted them to purchase directly. The benefit at that time (the dollar exchange rate was 30-32 rubles) was about 30-40 dollars, but with a guarantee it is more difficult for the Chinese, so I preferred to buy in Germany, knowing how the Germans treat warranty obligations. And I understand that I did the right thing, because the warranty for the inverter is 24 months and I had to send it in for repair twice. I only paid for shipping one way, so I think it was worth it.
Closer to summer, I decided to buy solar panels, and then it turned out that it was more profitable to buy batteries in Russia, since the Europeans raised the cost, and the popularity of solar energy grew in our country, and I didn’t take batteries from the highest price echelon. Thus, my solar power plant was able to generate 800 watts of energy. I had to buy a new controller, since I categorically did not want to switch to the main voltage of 24 V. The new controller was twice as powerful and could handle current up to 60A. My main consumers remained the same: household appliances, power tools (the inverter was already 12 V) and lighting. I also ordered the second inverter through Ebay, bargaining with various sellers for a long time, offering my price (there is such a fad) and even bargained for about $ 30. When I made such expensive purchases, the sellers, as a rule, sent the tracking code themselves to track the journey of the parcel, but it’s not shameful to ask for it yourself if they didn’t immediately send it themselves. I received all the parcels and everything worked successfully.
Keeping in mind that it is better to duplicate in offline important knots, I got a 12V and 2000 W inverter with a modified sine. He helped me out when the main inverter left for repair, so this approach justified itself. For the largest and most complex loads, like electric welding, I started the generator. And here it became clear that the generator could be useful when it was idling. I started looking at chargers that could charge such a battery pack.
A bit of theory. Lead-acid batteries are usually charged with a current of 1/10 of their capacity. Since I had two 190Ah batteries connected in parallel, the estimated total capacity was 380Ah and the charge current should have been around 38A. Such devices were either very expensive or were starter kits for starting a car engine. Choosing among our and foreign manufacturers for a long time, I came across a review from one user and began to dig further. Curiously, ZU Orion Vympel-50 produces Russian company, based in St. Petersburg. Judging by the reviews, the company listens to the wishes of users and produces fairly reliable and inexpensive chargers. The selected model allows you to issue a charging current up to 15A and has five charge profiles with three manual settings along the lower and upper voltage limits. Simply put, you can set up charging almost any type of battery, which is what I needed. To get 10% of the battery capacity, it was necessary to take a pair of chargers and connect them in parallel. By the way, the sun was enough so that the charge was not required, and now this charger is working on constantly maintaining the charge of the batteries.
The diagram shows a switch into which the power lines from the inverter and generator converge. This is a manual phase switch. Phase and zero are supplied to it from two power sources, and the output is fed to the load. Manually, it is possible, through the opening position, to select only one power supply, so I have protected myself from the possibility of shorting two power supplies. The option is extremely simple, but effective.
The result is a system that includes (2014 prices):
1. 8x100 W solar panels (~6500 r/pc)
2. Charge controller EPSolar Tracer 3215RN (~13000 r)
3. Charge controller mpsolar pcm60x (~16500r)
4. Inverter Solartronics 1500W (~ 16000 r)
5. Inverter Mystery MAC-2000 (bu for 1000r)
6. 2x Battery 190Ah (~8500 r/pc)
7. ZU Orion Vympel-50 (~ 3000r)
Total: 118500 r
What can such a system do? All summer I managed without a generator, even in not very clear weather. In cloudy times, consumption simply decreased, and in clear weather it was possible to successfully use a powerful power tool. The generator was started only for the use of electric welding. In order to use the energy received more efficiently, several tricks were used. The thermostat of the refrigerator was unscrewed to the maximum so that the refrigerator would work without stopping when it was turned on. Bottles with highly salty water were placed in the freezer, which served as cold accumulators and froze all day, giving cold to the main chamber at night. The refrigerator itself turned off at night. An electric bread machine was added to the electrical appliances, which consumed 650 Wh per cycle with a peak consumption of 600 W. Bread was baked almost every day. Thus, energy production exceeded consumption, but for powerful work like a welding machine or an iron, a generator had to be turned on.
Based on the results of creating the second version of the autonomy, we can conclude that:
a) buy sophisticated electronics on ebay Can
b) bargain before buying on Ebay possible and necessary
c) it is necessary to correlate warranty obligations and the difference in price between a device from China, bought from the Chinese and from Europeans
d) the cost of solar panels is inevitably decreasing and it is currently more profitable to buy them in Russia (in relation to Russians)
e) key devices should be duplicated so that in the event of a breakdown they will not be left without energy during the repair
e) be sure to separate the power circuits from different energy sources in order to prevent a short circuit
g) there are Russian analogues of all these devices, which often surpass Western or Chinese analogues in their characteristics
h) when buying in our stores, you can agree on a warranty replacement of key devices for the period of repair, in case of failure
At the end of the article, I would like to draw some conclusions. The built solar power plant cost half as much as a wind turbine, but it is effective from March to October. In winter, its production is only enough to provide lighting for the house, so the rather popular question in autonomous energy “is it possible to heat the house with solar panels” can be answered in the negative. If full autonomy is required all year round, then only a combination of two energy sources will allow you to live in a bright house. One of the sources is solar panels, and the second is a generator or windmill. In the case where there is a hydroelectric power plant nearby, the energy output is constant, with a few exceptions.
Dear Khabrovites, I noticed that many people were interested in the autonomous supply of energy and heat, therefore next material I would like to make it as useful as possible. In the comments, in addition to questions, please let me know what would be more interesting for you:
- The fight with power engineers for mains electricity and typical mistakes in the design of solar autonomy
- Reduce energy costs with solar panels
- We receive from the sun not only electricity, but also heat
- Is there life with a windmill?
The use of solar panels allows you to provide homes with free energy, especially in conditions of unstable power supply. However, this method has one drawback - in cloudy weather, the efficiency of the solar system is very low, and the house needs an additional source of energy. The use of various types of generators (gasoline, diesel) is inconvenient, since they require significant costs and are very noisy. The best way out is combined installations, including solar panels and wind turbines.
Such hybrid complexes make it possible to fully use the possibilities of natural energy and compensate for their individual shortcomings. For example, wind turbines, in principle, are not advisable to use without a backup energy source. The fact is that with several windless days in a row (which is by no means uncommon), the batteries are discharged too much, which negatively affects their performance and resource.
Solar batteries are ineffective in cloudy weather, which is usually accompanied by windiness. Thus, windmills and solar panels perfectly complement each other, ensuring constant battery charging and maintaining the power supply at home at the proper level. Another advantage is that solar systems do not require maintenance and fuel costs, while they are most effective in the summer, when wind speeds are usually lower.
In summer and sunny winter, the maximum energy production will come from solar panels. But in the cloudy off-season, when the cloudiness is significant and strong winds blow, windmills will mainly produce energy.
Composition of hybrid systems
Each combined solar-wind installation includes solar panels, a wind generator, a charging controller, batteries and an inverter. The power of the components is selected based on the needs of energy consumption. But you need to consider another factor - the type of wind turbine.
There are wind generators:
- Horizontal. These installations are cheaper, but they are effective in prevailing winds of one direction. In conditions of variable winds, their performance is minimal;
- Vertical. These energy sources cost about 2-3 times more than horizontal ones, but at the same time they work effectively even in the case of a constantly changing wind direction.
Thus, wind turbines and solar panels can fully ensure the energy independence of housing. In addition, such systems have more flexible configuration options than pure solar or pure wind installations. Their prices are quite reasonable as well.
For example, a system of a 600 W windmill and a 250 W battery (with a controller, inverter and battery) will cost about 85 thousand rubles. The plant will produce about 100 kWh/month.
Installation and switching
Elements are mounted in a hybrid system in the same way as in the case of an independent installation. Solar panels are placed on the roof or on a separate mounting truss (in this case, their inclination relative to the horizon can be optimally adjusted), and windmills are placed on masts near the house.
Despite the fact that when rotating, the blades of windmills make a specific sound (which many attribute to their shortcomings), they do not create additional inconvenience. The fact is that the sound is quite monotonous and not sharp, so people stop noticing it very quickly.
The connection is made by classical pattern. wind generator and solar panels through the controller they are switched to the battery, where the generated energy is stored. Consumers alternating current connected via an inverter.
Expenses
Like any other autonomous power system, a solar-wind plant requires a substantial initial investment. However, all investments pay off with complete energy independence from central networks. Such a system does not require maintenance costs. The payback of the project depends on the complexity of the installation and the load on the system, but on average it is 2-3 years. This period may seem too long, but keep in mind that electricity prices are constantly rising, in addition, connecting the cottage to the central power supply and installing the appropriate equipment (transformer, cable route) also require substantial costs.
Thus, for a home, installing a hybrid system will best solution. It is irrational to install such complexes in the dacha, since they are designed for year-round use, and the dacha is used mainly in the summer season.
Reader question:
I am preparing to build a country house in an area where there is no common electrical network, so I want to install an alternative energy system, but I don’t know which one to choose. There are opportunities to use various renewable resources, but I can not decide how to prioritize. Here are some evaluation facts that I have gathered:
- 3.3 hours of sunshine (daily average for the year) with minimal shading on my site.
- 3.5-4 m/s average wind speed at a height of 30 m tower, 10 m above the top of the tallest tree.
- A water flow with a height difference of 9 m to 120 m, about 0.15 m³/min is available all year round, with the possibility of a generator located 220 m from the house.
Hydro is said to be the "best" choice because it requires constant strong winds, and solar panels are more expensive but more reliable and likely to pay off in the long run. I may need multiple sources.
My electricity consumption is quite economical. At the moment, I consume about 8 kWh per day in my city apartment. I also plan to buy energy saving appliances, so I expect the consumption in my country house will not greatly exceed the city consumption. What should be considered when choosing an alternative system to avoid costly mistakes?
It's nice to deal with such a well-defined question. The most important parameter is the required energy production (8 kWh/day), although it is also important to consider losses. Energy is lost in wires, battery, inverter, load fluctuations, etc., so you need to calculate, on average, 12 kWh / day.
hydro generator is probably the cheapest source of energy. In addition, the hydroelectric power station also operates at night and in winter, which will save on the use of expensive batteries. You can estimate the available hydro power (watts) by multiplying the height difference and dividing by 10. In your case, a well-configured system can deliver 120 watts. In 24 hours it will turn out: 120 × 24 ÷ 1000 = 2.88 kWh / day. The additional costs for pipes and wires will be small compared to the benefits. If you install a hybrid solar-hydro power plant, additional kW in rainy weather will be especially pleasant when the performance of solar panels decreases.
While 3" pipes will work well with 0.15 m³/min, 4" piping will reduce pipe losses from 12% to 3% and also increase the capacity to 0.3 m³/min or more if available.
A distance of 220 meters is a fairly long transmission cable, so resistance losses must also be taken into account. Consider using a higher voltage generator connected via a precision tracking controller. maximum power(MPPT) to prevent overload. MPPT automatically manages the system as the flow changes, avoiding the need for manual adjustments under changing conditions.
solar power is the next option. The good news is that solar panel prices are falling. The photovoltaic system will complement the hydro system as it performs better in dry, sunny weather, but its performance can be disappointing in winter. Presumably, you can get about 70% of the required energy. For example, at 3.3 hours of sunshine, a 3 kWh battery produces about 7 kWh/day. Again, MPPT can help improve this picture.
Wind energy, perhaps, would be interesting, but in this case not the most rational. Installing a 30 meter tower is not cheap, and the energy produced at a speed of 3.5-4 m / s will not be much. Wind is an unsustainable source of power, requiring expensive batteries and a back-up generator. In terms of effort and cost, wind is more expensive and difficult choice for your area.
For a more accurate estimate, compare specifications manufacturers alternative systems. But be aware that they tend to provide optimistic data. Please note that you will get twice as much energy when average speed wind 5 m/s compared to 3.5-4 m/s. You can determine the average daily kWh output by dividing the annual output by 365. However, keep in mind that for many days there will be little to no output at all.
No matter which source you choose, you'll need an efficient backup battery. Try to minimize its use. Although, it may be needed to save your system when the natural conditions are against you. If your water source does run all year round and you are prepared for drastic reductions in energy use from time to time, you can avoid using large batteries.
In any case, before making the final decision on where to put your investment, make sure you know what to expect before taking the plunge.
Ecology of consumption. Homestead: To balance the flow of energy from alternative sources often there is a desire to combine solar panels and a wind generator in one system.
To balance the supply of energy from alternative sources, there is often a desire to combine solar panels and a wind generator in one system.
In what cases it is worth doing this and what source of alternative energy to choose, you can understand by considering the pros and cons of windmills and solar panels.
Advantages of solar panels:
- Reliability - quality panels from a well-known global manufacturer will work for 25 years or more, since they do not have moving parts and any electronics in their composition, and strained glass, durable aluminum frame and reliable sealing of the elements ensures trouble-free operation of the panels in all weather conditions at any temperature.
- Easy to install - with the help of standard fastening kits, you can easily fix the panels on the roof or on the wall of the house.
- Absence of necessity Maintenance - the only thing that is recommended to increase energy production is to wash the surface of solar panels once a year detergent for glass, but this is not necessary.
Cons of solar panels:
- Low average daily electricity generation in winter time - 5-10 times less than in summer for middle lane Russia, 2-3 times less - for the southern regions and the complete absence of generation in winter in the northern regions beyond the Arctic Circle. To compensate for the lack of electricity, it is necessary to use a diesel generator, gas generator or wind generator.
- Strong dependence of electricity generation on the weather. In cloudy weather, production is reduced to 5-20% compared to cloudless sunny weather. However, to eliminate this dependency in offline solar power plant You can use high-capacity batteries that provide a supply of electricity for 5-7 days.
Advantages of wind generators:
- Electricity generation does not depend on the time of day and season if there is wind.
- In areas where winds often blow (in the mountains, in the steppes, on the banks of rivers and seas), a windmill can generate a significant amount of electricity. However, the total area of such places inhabited by people, in Russian Federation accounts for less than 1% of all populated areas.
Cons of wind generators:
- The need for installation on a mast with a height of more than 25 meters in 99% of the territory of the Russian Federation , since residential buildings and forests greatly reduce the wind speed close to the ground, the cost of installing a wind generator will many times exceed the cost of the wind generator itself.
- With an average wind speed in Russia of 3-4 meters per second, the wind turbine will generate about 1-3% of its nominal capacity. The rated power of the wind generator is indicated for a wind speed of 10-12 m/s.
- Lack of reliability in the segment low-power windmills up to 10 kW - most cheap low-power windmills will not work for more than 2 years without breakdowns, although there are cases of windmills running for 8 years.
- The need for annual maintenance to keep the wind turbine running.
- Freezing of lubricant at negative temperatures leads to the impossibility of starting a windmill in winter.
- The whistle of low power windmills operating at high speeds at high wind speeds - will not bring pleasure to you or your neighbors.
- Low frequency infrasound powerful wind turbines at any wind speed and low-power ones at low wind speed - as you know, infrasound has a negative impact on human health and all living things. It is for this reason that industrial wind farms are located at a considerable distance from residential areas.
Summarize:
The use of a wind generator as an additional source of energy for a solar power plant makes economic sense only in areas where winds often blow, provided that it can be installed far from home. At the same time, it is necessary to install reliable powerful models with a power of 10 kW or more and it is imperative to carry out their annual maintenance. published
If you have any questions on this topic, ask them to specialists and readers of our project.
