Alaska Wind and Green Energy Information Site

Sooper Articles

Admin — Tue, 15 Nov 2011 06:01:36 +0000

Sooper Articles is a post from Alaska Wind Energy.

The Cost of Wind Energy for the Residential Home-How Practical is Wind Energy?

Admin — Mon, 14 Nov 2011 21:28:09 +0000

DIY wind turbines are used to utilize the energy of the wind and a lot of work has been done to make them more affordable. However, buying a wind energy system still requires a large investment, but there is a way in which you can cut costs significantly.

This technique to cut costs involves making your own wind energy turbine. Wind turbines are available in large and small sizes. Building your own turbine means that you will be able to control costs to a certain extent.

Wind energy systems have different components like a generator, rotating shaft, gearbox, mounting tower, etc. An understanding of how to put together the whole system is necessary for building your own turbine wind generator but this type of information is freely available online now.

DIY wind turbine manuals can help you with the entire process. These manuals contain instructions and diagrams that explain things in a step by step manner so that you do everything correctly. Many do it yourself guides and manuals are available online and the basic components can be purchased at most hardware stores.

Building your own turbine is a very practical way of providing electrical energy for your house. Small wind energy turbines can be used to power household appliances and lighting.

You have the choice to either choose a horizontal-axis wind turbine or a vertical-axis. In horizontal-axis turbines the blades are facing the wind direction, while in vertical they can be in different directions. Horizontal-axis wind turbines are the most commonly used.

The vertical-axis turbines are more suitable in places where wind direction can vary frequently.

You can setup your own wind energy system for as low as $200. A DIY wind turbine is economical and clean and will payback the initial investment in about 3 years.

Clearly there is a huge benefit to the environment also and you can play your part in reducing environmental pollution.

The Cost of Wind Energy for the Residential Home-How Practical is Wind Energy? is a post from Alaska Wind Energy.

Gets Full Eco-Friendly Moving Service as New York Movers

Admin — Mon, 14 Nov 2011 20:47:51 +0000

The Serenity Movers is environmentally friendly movers company. Inexpensive and stress-free moving can be the right way to start a new life. We are moved also electronics items, books, etc; we quote you to determine whether you need help packing items such as art can include the price of this service. Establish the cost of moving your household mover’s relocation consultant. Relocation consultant as part of the evaluation performs a detailed inventory of all items scheduled to be moved. Our Serenity Movers company motto is honest, reliable, professional Green, New York Moving companies committed to providing services to move, and eco-friendly full-service moving company based in New York City.

Serenity Movers, our neighbors in New York, highest quality, is committed to providing an affordable movers service. A positive attitude and professional handle the job well with a strong desire to move to help you easily migrate to a new location will be working with a team of experts trained and knowledgeable and respected. Serenity Mover New York company customer service is second to none our goal is to provide complete satisfaction to each and every client. You are not the typical face of a huge state enterprises may deal openly with the owner of Serenity Movers.

We understand the challenges of the world’s largest relocation of the city’s only local businesses in New York knows, we move you, to ensure that the smooth stress-free experience are using that knowledge. We will support you in your efforts to make earth-friendly. Serenity New York Mover is focused on providing green Relocation. We use biodiesel in our truck fleet, to use reusable plastic containers for recycling boxes and packaging. Our trucks are clean burning alternative fuel, biodiesel, hundred percent recycled paper products. We recycle all packing boxes and crates. Also, you can choose your most earth-friendly packaging equipment. All factors of the situation unique and needs a new home is. You can move in Manhattan, Brooklyn. We’re looking to move on Staten Island and Queens, the best service to residential customers in all these areas.

Each of your house, your old will provide a unique opportunity to work great, your belongings, devised our plans to move your personal. We also offer a flat rate plan is suitable for the mobile space from a bedroom larger than the best. Serenity Movers is offering a plan to meet the needs of the two highest prices. Our most popular plan is based on hourly rates. Our prices are very viable, the actual cost of any plan related to your move is determined that, when they visit your home relocation consultant. For more information about our mover service you can view online visit as serenitymovers.com.

Gets Full Eco-Friendly Moving Service as New York Movers is a post from Alaska Wind Energy.

Solar Power For Home Outdoor Lighting

Admin — Mon, 14 Nov 2011 19:56:33 +0000

Outdoor lighting is an important part of every home. This ensures safety and convenience of the people living in a particular house. These lights become even more important during stormy weather or at night. You might be thinking that these lights can not be powered up by solar energy because of the absence of sunlight during those situations. The best part about solar power for home is that it can be stored in batteries. That way, even if there is no sunlight, the sufficient electricity that is stored in the batteries can be utilized. Whether it is day or night, bright or cloudy weather, the outdoor lights will still function. The solar power for home will even reduce the expenses for electricity.

Functionality of Solar Power for Home Outdoor Lights

It is easy to tailor fit the outdoor lights according to your preferences even if it utilizes solar power as source of energy. Because of the varieties of available solar powered outdoor lighting fixtures, there are hundreds of options that you could choose from. There are those with replaceable battery packs and other programmable features. You can even set the time when it will turn on and off. The shapes and designs are almost endless too. Some light fixtures would work best not just for providing brightness but also for adorning pathways, plant boxes and even gardens. Solar power is a good option when it comes to providing sufficient illumination outside your home because it could power up compact bulbs, accent lights and even the bright flood lights.

Installing Efficient Solar Powered Lights Outside Your Home

Solar power for home outdoor lights can work efficiently if proper installation procedures are followed. These lights can provide sufficient brilliance at night if it is charged up well during the day. So, it is important to situate the lamps where it could get enough sunlight. For patios, the outer poles can be a perfect spot because it is hit by the sun’s rays during the day. For gardens, setting up a stand alone pole can be great too. If used as an embellishment for gardens, putting it among the edge of bushes, bird baths or fountains can certainly add more grace and beauty to a home’s facade.

Cost-Efficient Outdoor Solar Power For Home

It is true that solar powered light fixtures can be a bit more expensive than the traditional light bulbs and lamps. Yet, this is an investment that is absolutely worth it. Spending a little more for a solar powered outdoor light is a one time occurrence. On the other hand, traditional lighting systems that are connected to the main power grid will make you spend more money continuously because of the charges on your electric bill. That is why, the one time costs of solar power for home is a smart choice.

It is best not to be too stingy when buying outdoor light fixtures which uses energy from the sun. You have to remember that it will be subjected to changing weather conditions outdoors so choose the ones with good quality and ensured durability.

Solar Power For Home Outdoor Lighting is a post from Alaska Wind Energy.

Jatropha – Bio energy crop

Admin — Mon, 14 Nov 2011 06:56:57 +0000

Jatropha is the plant with many potential benefits. As the fossil fuels are declining rapidly and the carbon dioxide emission emitted from it pollutes the atmosphere, the world is working towards an alternative fuel to overcome it.

The Jatropha curcas is the plant which can grow in semi arid region, little care is enough for its growth. It grows both in topical and sub tropical region. The jatropha seed contains 35 percent oil content in it. The oil from jatropha can be used as biodiesel blend up to 20% without refining. The oil burns with clear smoke-free flame, and was tested successfully as a fuel for simple diesel engine. It is not a food crop since the oil is non-edible. The oil is used as a traditional medicine disinfectant and to cure diseases like cancer, piles, snakebite, paralysis dropsy etc. The seed oil is also used for lighting and in soap preparation. It is rarely used as a live fence in preventing crops from livestock and it occasionally used as property demarcation. It reduces the soil erosion.

The optimum growing conditions for the Jatropha plant ranges from 1000 to1500 mm annual rainfall, with temperatures of 20 to 28 C. The soil should be free draining with no water logging. But adequate water and nutrition is a must for high yield. The jatropha is easy to grow and it can bear the seeds within a year of planting. It provides oxygen for the planet and it can grow even in poor soil. It cannot withstand frost.

The Jatropha Electrification is developing in many countries. Mali is considered to be one of the poorest countries in the world. At Mali, Garalo Jatropha Producers’ Cooperative (CPP) and the power company ACCESS are the main institutions developing jatropha cultivation. The private power company ACCESS is generates and does electricity sales. Currently 247 households are connected to the micro grid after a payment of $30 as a contribution to the connection costs. Likewise in India, the Rural Electricity Supply Technology (REST) mission of the Ministry of Power (MOP) planning to produce power for all by 2012. The small scale power generation projects were established in Chattisgarh, India. It is being run by Winrock International in the Kabir Dham district. This small power system provides 24-hour power supply at the very affordable price of 50 cents per light bulb to poor villagers. It is 17.5 KW capacity power plant runs on raw jatropha seed oil .Jatropha is a promising crop for rural development. The jatropha oil lights up rural areas with electricity. The jatropha planting on the wastelands has the ability to provide 50-60% of the India’s fuel requirements.

The Jatropha curcas plantation in 1 hectare reduces 20 tons of carbon dioxide per year. The largest jatropha producing country in Asia will be Indonesia and India. In Africa, Ghana and Madagascar will be the largest producers. Brazil will be the largest producer in Latin America. The plantation is a labor intensive process hence it creates job for many poor rural people. Above all Jatropha can be used as a Renewable Energy.

Jatropha – Bio energy crop is a post from Alaska Wind Energy.

Switch to Cleaner Sources of Energy Like Wind Power And Solar Lighting

Admin — Sun, 13 Nov 2011 21:23:41 +0000

With decreasing quantities of commonly used energy sources it is essential that the world now shift its focus to renewable sources of energy. These forms of energy does not only cut down the energy cost but also help to prevent further deterioration of the environment. Sun is the largest source of energy and all kinds of renewable sources of energy are directly or indirectly linked to solar energy. Solar Lighting, biomass and Wind Power are some of the commonly used forms of solar energy. With countries across the world developing and investing on schemes to harness solar energy using these for household uses is no more an impossible task.

Solar Lighting- an eco friendly option-

Solar Lighting work by harnessing the energy of the sun and with technological advancement many feasible options are now easily available in the market. Earlier one may have worried about the fact that these will not match with their artistic décor, but with new designs this is no more a problem. These lights can be used to effectively light up any space and depending on the intended usage on can purchase from the vast number of available options. Mechanical sensor automatically turns on the outdoor light when the need for lighting appears.

Easy installation and an uninterrupted back-up even in case of a power failure have further increased the popularity of Solar Lighting; though, the biggest advantage of these lights continues to be the environmental benefit. Sun is a source of abundant energy and most importantly it is renewable. The saving on the electricity bills in the long run makes this kind of lighting a smart investment. With more and more money being spend by leading economies the operating costs will definitely be further reduced making it more feasible.

Wind Power- an excellent manner to harness solar energy-

Wind is another form of solar energy which has been put to effective use since long. There are many countries in the world toady which are investing huge sums on wind farms and this investment has already been paid off by the huge production of energy. Wind Power is one of the cleanest sources of energy and there is no emission of gases or unwanted wastes during the entire operation. The modern technology makes it very easy to capture the wind energy and put it down to maximum usage.

Planned and detailed planning can help Wind Power to become the main source of energy especially in areas which are located in favorable geographical locations to do so. Wind turbines can be easily installed and help meet if not complete, a substantial part of the energy demand. Wind Power is ample and with no negative effects on the environment it can be used as an energy source for a cleaner future.

Solar energy can provide with the right energy solutions for large industries as well as small household. Individuals and nations can not only cut expenditure using these forms of energy but also do their bit to contribute to a pollution free environment.

Switch to Cleaner Sources of Energy Like Wind Power And Solar Lighting is a post from Alaska Wind Energy.

Renewable Electricity Energy Suppliers

Admin — Sun, 13 Nov 2011 20:52:31 +0000

The energy market is growing exponentially, and it shows no signs of stopping.

The market shows many signs of diversification, which is a very good thing-investment in oil is becoming secondary to investment in things like renewable energy sources and research. This is very good news for the environment and energy suppliers.

One of the most important energy suppliers in the western world is a corporation known as Amelot Holdings. This corporation builds plants to synthesize ethanol and purify biodiesel. It has mainly been active in the United States, but recently, it has been attempting to branch out and acquire more researchers and production sites for ethanol and biodiesel fuels. Amelot Holdings is an energy supplier looking for expansion: construction contracts, joint ventures, and mergers.

Another active energy supplier is Environmental Energy. The corporation known as Environmental Energy has a subsidiary company that is called Microgy. This company, Microgy, is essentially a research arm of Environmental Energy: it conducts research in the areas of biogas and agricultural waste, trying to reduce our international dependence on fossil fuels and other non-renewable resources. The fuels being developed my Microgy may someday be used to power cars, heat buildings, and many other potentially unforeseen applications. The best part about this potential fuel source is that it is “green”-that is, it is an entirely renewable source of energy.

Environmental Energy is an energy supplier that operates a variety of different types of energy facilities. It has been in operation since 1982, and has projects that utilize municipal waste, hydroelectric plants, clean gas generators, and energy recovery systems. Unlike many energy suppliers, Environmental Energy’s board of directors is comprised of concerned parties from the public and the private sector. This gives them a unique perspective on issues such as finance, energy conservation, and agriculture.

One of the leading energy suppliers of electricity is Intrepid Technology and Resources, Inc. (henceforth RTI). RTI uses municipal and human waste to produce natural gas. Their company is striving to end the world-wide dependence on fossil fuels and other non-renewable resources by creating a renewable and viable form of energy from waste that humanity must dispose of anyway. RTI has improved technology to the point that methane gas is now accepted in many circles as a viable substitute for natural gas.

The newest rising star in the renewable electricity market is Nathaniel Energy. This energy supplier seeks to halt the damage being done to the environment and potentially reverse it in the future. They also seek to help small-business owners by trying to reduce the cost of owning one’s own business to a reasonable amount. Nathaniel Energy offers special benefits to small and green businesses.

Many energy suppliers are slowly coming around to the inevitable change that must take place for the world to continue to function, but the international community is still incredibly dependent upon non-renewable fuels and resources to function properly. Investing time and money into green energy suppliers may seem like a long shot now, but for the future, it is the best thing that can be done.

Renewable Electricity Energy Suppliers is a post from Alaska Wind Energy.

The Society Needs The Support of Solar Power Los Angeles

Admin — Sun, 13 Nov 2011 19:55:28 +0000

We all take great pride in our species and make every effort to tell about our glorified history to all. Human beings are considered to be the most intelligent animal living in the face of earth. This is because out of millions of species living in this planet, we are the ones who are gifted with the quality to differentiate between right and wrong when time comes. This quality offers us with a stature not less than any god sitting there in heaven. Throughout our lives we are taught that the most dominant breed on this part of galaxy is us and only us.

The longevity of our talent of judgment is supposed to determine the life of earth. Many among us believe that now is the time when we all are losing our judgment capacity and often taken the side of wrong deed.
If this keeps on going like this, in near future we all are going to be the ones nailing our bright fate in coffin. The existence of our being is because of some elements presence in the earth. Energy sources are one of the most vital that falls in this list of necessary items. There is an alarming rate of fall in its amount, more precisely the non-renewable sources. This is the ripest time to think about solar energy and water energy. In various parts of the world the wind energy and tidal energy are offering much to the development of the civilization and society inhibiting on that particular space. Solar power Los Angeles is a name gradually becoming popular among common masses of the nation for offering fine collection solar panels to be installed in various parts like domestic and official spaces.
Over the year the world has seen many new forms of developments in various niches and more precisely on those parts which were not imaginable by all. Solar power Los Angeles is one such thing that is fast eradication the electrical lighting appliances from common household and altering that with solar energy dependent accessories. This has huge amount of benefit attached with it. People no more have to be dependent on government for supply of electricity and they no longer have to pay heavy electric bills. Solar energy is very much environment friendly and by using it no harmful gases or any other substance gets emitted in air. This way we all can contribute to nature and make the life of our future generation healthier.
If you are looking to contribute some from your end using solar energy Los Angeles panels is the best way to do it. With few years of implementing these in the city a drastic fall of harmful gages can be seen in the surrounding environment. This might be the strong reason behind the success of very popular solar systems Los Angeles. The affordability of prices also plays a very vital part in its world-wide acceptance. Along with usability these offers us with a hassle-free way to conserve nature’s resources and benefitting us all in the long run.

The Society Needs The Support of Solar Power Los Angeles is a post from Alaska Wind Energy.

Wind Turbine – Cutting Edge For Providing Reliable And Efficient Power

Admin — Sun, 13 Nov 2011 05:57:27 +0000

Generating electricity without any problem is one of the major requirements in today environment. We always try to find out the new ways to generate electricity without providing any harm to environment and the also which did not made any contribution to the global warming. Energy from the renewable sources is the best example and easily available alternative.Wind turbine is one of the sources of renewable energy. It is used to generate electricity with the help of wind. It can be setup anywhere as no hectic and major requirements needed in making the setup of wind turbine. Only wind is required by the wind turbine, wind is freely and easily available everywhere and all the time as well. There are various kinds of wind turbines available, horizontal axis turbine is the most common type. It is surrounded by blades like the propellers on the airplane. Vertical axis turbine is another kind of wind turbine that also has blades, but they run from top to bottom. Wind turbine works as follows: The blades must face the direction of the wind. When they move, they turn a drive shaft within, which in turn powers a generator. This creates electricity. Wind turbines can be used at homes or at business organization as the alternate to generate electricity. As they do not emit any poisonous gases, it is safe for the workers to work at the other side of the field as they can be setup in a small portion of the field. Advantages of wind turbine:Wind can be easily available and captured easily with modern technology.ï‚§ Wind can be easily available and captured easily with modern technology.ï‚§ Wind does not produce any green house gases or other pollutants.ï‚§ Wind turbines can be setup in a small portion of land.ï‚§ Remote areas which do not have supply of electricity can use wind turbines for this purpose.ï‚§ Available in many different sizes and ranges.Apart from the above advantages there are many disadvantages of wind turbine as well discussed below:ï‚§ Wind turbines are noisy.ï‚§ At the time of manufacturing wind turbines some pollution is produced.ï‚§ Mostly large farms are needed for their setup.ï‚§ Lastly, the power is not constant and it varies from zero to storm force.

Generating electricity without any problem is one of the major requirements in today environment. We always try to find out the new ways to generate electricity without providing any harm to environment and the also which did not made any contribution to the global warming. Energy from the renewable sources is the best example and easily available alternative.

Wind turbine is one of the sources of renewable energy. It is used to generate electricity with the help of wind. It can be setup anywhere as no hectic and major requirements needed in making the setup of wind turbine. Only wind is required by the wind turbine, wind is freely and easily available everywhere and all the time as well.

There are various kinds of wind turbines available, horizontal axis turbine is the most common type. It is surrounded by blades like the propellers on the airplane. Vertical axis turbine is another kind of wind turbine that also has blades, but they run from top to bottom.

Wind turbine works as follows: The blades must face the direction of the wind. When they move, they turn a drive shaft within, which in turn powers a generator. This creates electricity. Wind turbines can be used at homes or at business organization as the alternate to generate electricity. As they do not emit any poisonous gases, it is safe for the workers to work at the other side of the field as they can be setup in a small portion of the field.

Advantages of wind turbine:

Apart from the above advantages there are many disadvantages of wind turbine as well discussed below:

Wind Turbine – Cutting Edge For Providing Reliable And Efficient Power is a post from Alaska Wind Energy.

About Urbane Wind Turbine Investment

Admin — Sat, 12 Nov 2011 21:31:31 +0000

About urbane wind turbine investment

These costs consist of: complete UWT installation including the engineering, safety measures, monitoring, supporting construction, transport and mounting, proof of operation (commissioning) and the acceptance. Likely additional costs will arise from:

feasibility studies, location selection, structural assessments (if mounting the turbine on a building), obtaining permits and project management. In order to at least partially compare the investment costs of the different turbines, the cost per kW installed has been calculated. The figure provided is the result of: (total investment – remaining value after 10 years) / nominal capacity.

The remaining value has been estimated as 20% of the investment for all turbines except for Ropatec. This is because the manufacturer of Ropatec guarantees to buy back his turbine after ten years for a fixed price. However, it should be noted that all costs are estimates at the time of publication and could change.

Also, all calculations are only indicative, as the separately charged costs cannot be estimated and the performance figures provided by the suppliers and manufacturers have not been verified in practice. Therefore, although these figures provide a rough guide to costs, further investigation on an individual project basis is necessary.

4.1.2 Periodic costs

The periodic costs include maintenance, part replacements, transport costs related to the on-site work, the possible insurance costs (including the third party damage liability), the costs of any equipment replacements and the cost of a complete check of the system after 10 years of operation. Again, these costs have been estimated on the basis of information from suppliers and manufacturers and should be treated as indicative costs only.

4.2 Benefits

4.2.1 Financial incentives

The financial incentives available differ between the Netherlands and the UK.

The Netherlands: E.I.A. – Energy Investment Deduction for profit-making organisations: it is possible to obtain the E.I.A. with a maximum of € 5000 per turbine for turbines with a nominal power < 25 kW.

M.E.P. – Electricity Generation Environmental Quality: applies to the total energy generated by a renewable energy installation. The level of the M.E.P. subsidy per kWh is set by the government and laid out in the Ministerial grant scheme regulation.

UK: A grant can be obtained from the Low Carbon Building Programme (LCBP) in the UK, to cover up to 50% of the installation cost.

Some provinces and municipalities provide additional subsidies as a part of their own renewable energy development programmes. Most commonly these

subsidies are a part of local measures against climate change and are usually reconsidered yearly.

4.2.2 Savings through using of the generated electricity

Using the electricity generated at the location means direct savings for the owner through a lower electricity consumption bill. The savings depend on the price

paid to the electricity supplier by the consumer for electricity supplied from the grid. For example, the customers of the supplier ENECO in The Netherlands pay approximately 21 €cents/kWh. In the UK, typical cost of electricity for flats and households can range from 11p to 16p/kWh. These prices depend very much on the time during the day (or night) when the electricity is used.

Selling to the grid

If there is a surplus of electricity generated from a small wind turbine, in theory it can be sold and the owner decides to whom. Most commonly it would be sold to

an electricity supply company. The price can differ considerably from one electricity company to another, so it is worth investigating several options. For example, in the Netherlands, ENECO pays 4.088 €cents/kWh excluding VAT (2007).

The electricity supplier Green Choice gives discount on the supplied electricity to his customers who feed their energy surplus into the grid. Selling electricity to the grid is regulated differently in each country. If the owner of a UWT wants to sell his electricity to the grid, (s)he may need to have a specific type of meter that measures both ways: the electricity sold to the grid and the electricity consumed from the grid. This type of meter is readily available but is not installed as standard and so may need to be installed as part of the wind turbine installation.

4.3 Efficiency of UWTs

The efficiency of wind turbines is most commonly measured in terms of cost-effectiveness, i.e. in cost per kWh of the produced electricity. In a technical context in order to determine the revenue generating potential, the efficiency would be measured as a yield, measured as the number of kilowatt-hours produced per square meter of rotor area per year (kWh/m2/yr).

At this moment there are insufficient yield figures for UWTs from real projects to draw definitive conclusions on efficiency. This means that the efficiency can only

be estimated and that the comparisons between various types of UWTs cannot be done reliably.

Nevertheless, an indicative comparison is provided in Tables 4

and 5 by using the “reference yield” from the manufacturer calculated at two specific wind speeds namely:

o 12 m/s: a figure close to the nominal wind speeds of most UWTs

o 5.5 m/s: a good average wind speed for operation of the investigated UWTs.

Explanation:

A = rotor area

Vnom, Pnom en A have been provided by the vendors (see table 2). Pref is the result of the formula: Pref=(vref/vnom)3 x Pnom

Comparison with large turbines

The initial (capital) investment per kW can vary greatly between different UWTs: according to the information provided by suppliers and manufacturers it can be between 2,400 and 9,100 €/kW. In comparison, the initial investments for large turbines are about 1000 €/kW for land installations and about 2000 €/kW for offshore (investments in solar photovoltaic (PV) systems are approximately 6,200 €/kWp installed).

The expected yield, assuming there is an average wind speed of 5.5 m/s, would very approximately amount to 150 – 400 kWh/m2/year. The yield of large turbines

varies between 800 and 1200 kWh/m2/year.

The figures indicate that large turbines clearly outperform UWTs and this is not surprising, as the conditions under which they are implemented are very different.

However, UWTs are still in a development phase and although it is unlikely that they will ever reach the yields of large wind turbines (since wind resources are not the same in urban environments) it can be expected that costs will fall and the efficiency of UWTs will be significantly improved. Manufacturers of UWTs in the

Netherlands and the UK expect a price reduction of about 40% by a ramped-up production of at least 500 turbines per year.

Finally, UWTs generate electricity that can be directly consumed at the site of generation. This means that the produced electricity is effectively being used

against the consumer price which is approximately 5 times higher than the price paid for the electricity produced by large turbines.

Considering the installation capacity, costs and the expected yield, it is better to compare the UWTs with solar PV production of electricity.

About Urbane Wind Turbine Investment is a post from Alaska Wind Energy.