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Renewable Energy Basics

By
Oliver Gordon
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0

Renewable Energy Basics
We currently rely heavily on coal, oil, and natural gas for our energy. Fossil fuels arenonrenewable, that is, they draw on finite resources that will eventually dwindle, becoming too expensive or too environmentally damaging to retrieve. In contrast, renewable energy resources—such as wind and solar energy—are constantly replenished and will never run out.
Solar
Most renewable energy comes either directly or indirectly from the sun. Sunlight, or solar energy, can be used directly for heating and lighting homes and other buildings, for generating electricity, and for hot water heating, solar cooling, and a variety of commercial and industrial uses.
Wind
The sun’s heat also drives the winds, whose energy is captured with wind turbines. Then, the winds and the sun’s heat cause water to evaporate. When this water vapor turns into rain or snow and flows downhill into rivers or streams, its energy can be captured using hydropower.
Biomass
Along with the rain and snow, sunlight causes plants to grow. The organic matter that makes up those plants is known as biomass. Biomass can be used to produce electricity, transportation fuels, or chemicals. The use of biomass for any of these purposes is called biomass energy.
Hydrogen
Hydrogen also can be found in many organic compounds, as well as water. It’s the most abundant element on the Earth. But it doesn’t occur naturally as a gas. It’s always combined with other elements, such as with oxygen to make water. Once separated from another element, hydrogen can be burned as a fuel or converted into electricity.
Geothermal
Not all renewable energy resources come from the sun. Geothermal energy taps the Earth’s internal heat for a variety of uses, including electric power production, and the heating and cooling of buildings. And the energy of the ocean’s tides comes from the gravitational pull of the moon and the sun upon the Earth.
Ocean
The ocean can produce thermal energy from the sun’s heat and mechanical energy from the tides and waves.
Hydropower
Flowing water creates energy that can be captured and turned into electricity. This is called hydroelectric power or hydropower.

Source….National Renewable Energy Laboratory.





Southern African Alternative Energy Association (SAAEA) represents and actively promotes Renewable Alternative Energy Solutions in our region. Its focus is the whole industry, rather than one sector.
Wind, Solar, Bio Fuels, Green Products, Energy Saving, Alternative Energy, Energy from Waste, Fuel Cell Technologies.

Wind Power Basics for beginners.

By
Oliver Gordon
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0

We have been harnessing the wind’s energy for hundreds of years. From old Holland to farms in the United States, windmills have been used for pumping water or grinding grain. Today, the windmill’s modern equivalent—a wind turbine—can use the wind’s energy to generate electricity.

How It Works

Wind turbines, like windmills, are mounted on a tower to capture the most energy. At 100 feet (30 meters) or more aboveground, they can take advantage of the faster and less turbulent wind. Turbines catch the wind’s energy with their propeller-like blades. Usually, two or three blades are mounted on a shaft to form a rotor.
A blade acts much like an airplane wing. When the wind blows, a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure air pocket then pulls the blade toward it, causing the rotor to turn. This is calledlift. The force of the lift is actually much stronger than the wind’s force against the front side of the blade, which is called drag. The combination of lift and drag causes the rotor to spin like a propeller, and the turning shaft spins a generator to make electricity.

Applications

Photo of a row of eight, large three-bladed, wind turbines on a sunny day.

These wind turbines near Lamar, Colorado, are part of the 162-MW Colorado Green Wind Farm. Each turbine produces 1.5 megawatts of electricity.
Wind turbines can be used as stand-alone applications, or they can be connected to a utility power grid or even combined with a photovoltaic (solar cell) system. For utility-scale (megawatt-sized) sources of wind energy, a large number of wind turbines are usually built close together to form a wind plant. Several electricity providers today use wind plants to supply power to their customers.
Stand-alone wind turbines are typically used for water pumping or communications. However, homeowners, farmers, and ranchers in windy areas can also use wind turbines as a way to cut their electric bills.
Small wind systems also have potential as distributed energy resources. Distributed energy resources refer to a variety of small, modular power-generating technologies that can be combined to improve the operation of the electricity delivery system.


Source…National Renewable Energy Laboratory


Read more at AWEA

Southern African Alternative Energy Association (SAAEA) represents and actively promotes Renewable Alternative Energy Solutions in our region. Its focus is the whole industry, rather than one sector.
Wind, Solar, Bio Fuels, Green Products, Energy Saving, Alternative Energy, Energy from Waste, Fuel Cell Technologies.

Solar Power Basics

By
Oliver Gordon
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0
Photo of a solar electric system in Colorado with snow-covered mountain peaks in the background.


Solar is the Latin word for sun—a powerful source of energy that can be used to heat, cool, and light our homes and businesses. That’s because more energy from the sun falls on the earth in one hour than is used by everyone in the world in one year. A variety of technologies convert sunlight to usable energy for buildings. The most commonly used solar technologies for homes and businesses are solar water heating, passive solar design for space heating and cooling, and solar photovoltaics for electricity.
Businesses and industry also use these technologies to diversify their energy sources, improve efficiency, and save money. Solar photovoltaic and concentrating solar power technologies are also being used by developers and utilities to produce electricity on a massive scale to power cities and small towns

Concentrating Solar Power 

These technologies harness heat from the sun to provide electricity for large power stations.

Passive Solar Technology 

These technologies harness heat from the sun to warm our homes and businesses in winter.

Solar Photovoltaic Technology 

These technologies convert sunlight directly into electricity to power homes and businesses.

Solar Water Heating 

These technologies harness heat from the sun to provide hot water for homes and businesses.

Solar Process Heat 

These technologies use solar energy to heat or cool commercial and industrial buildings.
Source….National Renewable Energy Laboratory
Southern African Alternative Energy Association (SAAEA) represents and actively promotes Renewable Alternative Energy Solutions in our region. Its focus is the whole industry, rather than one sector.
Wind, Solar, Bio Fuels, Green Products, Energy Saving, Alternative Energy, Energy from Waste, Fuel Cell Technologies.

Wind power asset management

By
Oliver Gordon
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0
Wind operators must squeeze out every watt they can when the wind is blowing. To do so, wind projects must be reliable and maintained with minimum cost. With variable winds, high costs, and slim margins, everything has to work right to make sure that wind is attractive alternative power and a sound economic investment. So if a turbine is to work 20 years or more before retiring, it better be properly designed and maintained.

Standard procedures: not working

Most wind turbines are maintained by a combination of traditional schedule-based preventive maintenance and threshold-based alarm systems. A problem with scheduled maintenance is that the standard six-month interval between inspections may be too long to detect an emerging problem. And fixed-threshold alerts, typically set by OEMs, activate too late to support proactive maintenance. That’s because the alerts are intended to protect equipment from catastrophic damage and can’t take into account a wide range of normal wind-turbine operating conditions and unit-to-unit manufacturing variances. As a result, typical fixed-threshold-alert systems do not detect problems until after a failure occurs.

Likewise, traditional condition-monitoring and predictive maintenance tools, such as vibration analysis, oil analysis, and thermography, are limited because of the difficulty in accessing the typical wind-turbine nacelle, the variable nature of the machine, and the time limitations and analytic capabilities of the technicians using them.

Ideally, equipment maintenance should only be performed when something needs fixing. Most preventive maintenance works on the idea of regularly inspecting or servicing equipment to address potential failures before they progress. However, given the huge variations in operating profile and environment, it’s easy to see that the regular, fixed inspection interval of traditional preventive maintenance may not catch critical emerging problems in the wind environment.

The conventional power industry, however, leads the industrial world in predicting impending equipment problems before they occur. And it is doing so using a technique directly applicable to the wind industry. In fact, several wind companies, Invenergy in Chicago for one, already uses the technology to get early warnings, avoid surprises, and improve control of their operations. The industry reduces risk exposed by existing condition-monitoring tools by leveraging its SCADA data to remotely detect emerging problems in a method is called predictive analytics.

Briefly, the technology precisely identifies impending problems by detecting subtle changes in equipment operation. It has found problems earlier than OEMs’ alerting systems or other condition monitoring approaches, and well within traditional alarm limits.

The Availability and Performance Center at SmartSignal’s headquarters near Chicago use predictive analytics to monitor a range of plants and equipment, wind farms among them. Invenergy’s U.S. fleet of 975 GE 1.5 MW turbines are monitored this way.

A predictive analytics primer

It’s a real-time system that works by analyzing SCADA data once every 5 to 10 minutes. The data for a turbine includes its power output, wind speed, rotor rpm, lube temperatures, and so on. Predictive analytics compares real-time data to a software model of equipment when operation in good condition, and compensates for normal variations due to load and ambient conditions. Further, the method uses software models customized for individual pieces of equipment to provide the earliest possible warning of emerging problems. It readily integrates with an existing data infrastructure and it’s quick and easy to deploy, maintain, and use.

The method needs no new sensor and analysts need not review masses of SCADA data. Instead, the software analyzes data and alerts analysts only when it detects an exception, providing ample time to plan and respond. And, by using algorithms to identify pattern changes, the analysis is highly accurate.

For wind applications, the software uses models customized for each individual turbine, which considers for fluctuations in wind speed, direction, and ambient conditions. In real time, the software compares data collected in the nacelle to the model–literally tens of thousands of data points every 5 to10 minutes across a fleet–and notifies maintenance and engineering of impending problems. Owners then focus on fixing problems early, before catastrophic damage occurs.

Take a gearbox for example. During the initial system configuration, a gearbox model would be “trained” using representative data provided from a data historian such as OSI PI (a data historian is a database for storing time-series data from instrumentation). Typically, one year of data would be used to train the model. In live operation, data from relevant sensors on the gearbox, such as for vibration and temperatures, along with operational state information, such as power output and ambient temperature, would be compared to the model. It would then provide an “estimate” of what each value such be, based on how it was trained from the historical data. If the actual value statistically differs from the model estimate, the system generates an alert. Technicians would review the sensors in alert and develop a preliminary diagnosis of the problem. A next step would typically be further on-machine investigation or use of other techniques, such as oil sampling.

Best practices

Given the high capital intensity of the wind-power business, reliable, long-term operation of the equipment is critical for generating positive returns and continued industry growth. It won’t take many major equipment failures before the long-term profitability of a farm is lost. As assets age, performing major work only when needed will be critical to maintaining economic viability.

Remote monitoring and condition-based maintenance approaches will be required to maintain financial returns because wind turbines are hard to access and don’t receive the same “walk-around” monitoring typical of industrial plants. Although wind has unique characteristics, wind turbines are just another kind of machine and successful operators will take advantage of best practices from other industries to outstrip their competition.

Source..Windpower Engineering

Top 6 Tips for Clean Tech Events and Renewable Energy Conferences

By
Oliver Gordon
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0

How do you make the most out of your attendance? No matter whether it’s an event on energy efficiency, solar energy, wind energy, green building or sustainable transportation, there are a few things common to each that will help YOU make your participation a success.
Just in time for your next clean tech event or alternative energy conference, here are our tips:
1) Have a game plan. Most events are overwhelming, and trying to find someone at the event is often impossible. That’s why it’s imperative that you reach out at least two weeks in advance of the event to target the top three people you’d like to have ten minutes with.
2) Talk into the microphone and identify yourself.  When you ask a question from the audience, it’s time to brand yourself and your company. Nothing makes a worse impression than someone who doesn’t give their name and company, mumbles and has not formulated a question. Oh, and make sure you ask a QUESTION. Leave the monologues to super villains.
3) Swallow the microphone. Many people are afraid of the sound of their own voice. They believe that holding the microphone around their waist or leaning back in their chair while talking on a panel somehow insulates them from the impact of their words. Wrong. If you have something to say, make sure everyone hears it.
4) Make friends with the people running the conference. They have a master list of emails and phone numbers, and probably know a lot of the attendees on sight. They can make connecting with the right person so much easier.
5) The most powerful word is “hello.”  It’s usually all you need when meeting someone to get their attention. We’ve seen it work wonders with strangers.
6) Have a business card conveniently ready. Digging through your briefcase, purse, satchel or suit sends a message about how you’ll handle a project. And it’s not a pretty message.
Source…

CleanTechies

Canadian Small Wind Turbine Manufacturer seeking South African Distributor

By
Oliver Gordon
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0

Global Wind Group is seeking a major distributor for the African market to appoint agents in various countries around Africa to solicit and install the ZuS modular power systems.

With the rising cost of energy there is a real demand for affordable energy alternatives. We’ve recently launched a turn-key product called the modular power system, and the response has been excellent.

The modular power system is a complete stand-alone modular power station which comes standard with:
VAWT Wind Turbine
Generator
Controller
30ft Composite Pole
Batteries

The modular power system is a versatile product and is the solution to customer’s energy, lighting, security, and telecommunications needs. The modular power system is a modular power station capable of supplying power to:
Residences and businesses
Street lighting, new or existing
Traffic control
Wireless video cameras
Telecommunications (WI-FI and Cellular)



The uses and location of the modular power system is endless. Below are some examples:
Golf Courses
Remote Areas

Telecommunication Towers
Street Lights

Street Lamps

Power for Security Cameras
Rural Border Crossings

Pathway Lighting

…and the list goes on

Distributor
“We identify a company or companies to distribute our product within the given territory. The distributors then have an inventory of our product to supply the agents in the given territories. Distribution companies with warehouse space, logistics set up, well-established, good reputation, experience in the renewable energy sector (not mandatory but preferred) are who we are seeking. The distributor profits from volume sales. Outside of North America the distributors are trained here in Winnipeg, Canada and then they offer the installation and sales training to the local agents.
Agents
The agents sell our products to the end users or through their resellers. The agent is responsible for the installation of the product and receives a 15%-20% commission on all sales (depending on quantity) and excluding installation. We provide the agent with all the marketing materials, training and support to help them succeed in representing our products. The agent is responsible to attend sales and installation training at the distributors head office within the first 3 months of signing the agency agreement. The costs associated with travel, accommodations, etc are the agent’s responsibility. It is not mandatory to buy a unit to become an agent; however we strongly suggest that they do to help market the product in their territory. We also offer incentives to agents who hit and exceed their sales targets.

Prior to becoming a distributor/agent or receiving any pricing or manuals, we ask that the interested party signs a non-disclosure form. At which time we will then supply all the packages for either program.”

For an introduction or more info contact SAAEA

Worm-Farming…Important Tips.

By
Oliver Gordon
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0
worm farm girl

News from Paul Maher at Worm-Farm.co.za
Freezing Food 
I know a number of people who take the time and effort to liquidise the food that goes into their worm farm. I achieve a similar (although not quite as good) effect by freezing the food that goes into mine.
Freezing bursts the worm food’s cell walls which means that it will decompose quicker once defrosted, this helps the worms eat the food easier.
Another big advantage of freezing food is that it kills any insect eggs. When you leave vegetable peels and fruits lying around in the kitchen, very often fruit fly will lay their eggs on them. This means that although you will be trying to keep fruit flies out of your farm you will be introducing them with the food. Freezing then is a big advantage.
Our kitchen never really produces a consistent amount of waste. Some days we have a lot and some days we have a little. I put all our vegetable peelings into a ice cream container and when this is full it is emptied into a bag and it is frozen. This will keep for many months and it can be used when it is needed.

Overfeeding
One of the more common problems I come across when looking at what goes wrong with peoples worm farms is overfeeding. A lot of people think they are being kind and overestimate the amount that their worms can eat. This can result in the contents of the farm rotting, becoming acidic or anaerobic and killing the worms.
When a farm is first established it usually has a starter amount of worms which can weigh anything from 100-400 grams, these worms will only eat 50-200 grams a day. So until the worms have had a chance to multiply only feed a handful of food at a time and wait for the food to disappear before feeding more. Rather put the food in your freezer until it is needed.

Invited to exhibit at GREENEX2010

Solar energy is the most readily accessible resource in South Africa.

By
Oliver Gordon
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0

Solar energy is the most readily accessible resource in South Africa. 


Most areas in South Africa average more than 2 500 hours of sunshine per year, and average solar-radiation levels range between 4.5 and 6.5kWh/m2 in one day.
 The southern African region, and in fact the whole of Africa, has sunshine all year round. The annual 24-hour global solar radiation average is about 220 W/m2 for South Africa, compared with about 150 W/m2 for parts of the USA, and about 100 W/m2 for Europe and the United Kingdom. This makes South Africa’s local resource one of the highest in the world.
Picture

Water-heating accounts for between 30% to 60% of the energy consumption in the average household. In South Africa, this derives mainly from electricity, being the most common energy-carrier employed. Removing this expenditure could lead to significant improvements in the disposable incomes of homeowners.

The equivalent of a large coal-fired power station (2 000MW+) is used to provide hot water on tap to the domestic sector alone. Since the inception of the accelerated domestic electrification programme through grid extension, a major distortion of the national load curve has emerged, with the early evening load peak growing significantly. 
 Modelling indicates that the introduction of solar water-heating can ameliorate the situation substantially. Switching from electrical to solar water-heating can, therefore, have significant economic and environmental benefits.

There are economic benefits for home owners in reducing their energy bills. Expensive generation capacity to address load peaks will be obviated, and the introduction of new base-load capacity will be postponed. Benefits for the country include reducing greenhouse gas (GHG) emissions, and the release of scarce capital for other pressing needs.

Solar water heaters have many benefits both for the customer and for South Africa. The customer benefits by having a reduced electricity bill and the country benefits because less power has to be generated by Eskom and so less pollution is generated.


Understanding the components of a small wind turbine

By
Oliver Gordon
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0

Mariah Power Tilt Down Tower installation
Home wind energy systems generally consist of blades, a rotor, a generator or alternator mounted on a frame, a tail (usually), a tower, wiring, and “balance of system” components ie. controllers, inverters, and/or batteries. The spinning of the blades enables the rotor to capture the kinetic energy of the wind and convert the linear kinetic energy into rotary motion to drive the generator.
Wind Turbine
Most turbines manufactured today are horizontal axis upwind turbines with two or three blades, which are usually made of a composite material. Some systems will have more blades then two, but testing has proven that though more blades will increase the wind speed operating range it will ultimately decrease the power output.
The amount of power a wind turbine will produce is determined primarily by the diameter of its rotor. The diameter of the rotor defines its “swept area,” or the quantity of wind intercepted by the turbine. The wind turbine’s frame is the structure onto which the rotor, generator, and tail are attached. The purpose of the tail is to keep the turbine facing forward into the wind.
Tower
In general, wind speed and consistency of wind resources increase dramatically with height. Because wind resources increase with height, the turbine will be mounted on a tower. Generally, the higher the tower, the more power a given wind system can produce. The tower also raises the turbine above the air turbulence that can exist close to the ground because of obstructions such as hills, buildings, and trees. A rule of thumb is to install a wind turbine on a tower that is at least twice the height of any obstructions within 500 feet. For more on tower height and set backs read Determining Setback Distances and Height for Small Wind Turbines. Keep in mind, relatively small investments in increased tower height can yield very high rates of return in power production. For instance, to raise a 10 kilowatt generator from a 60 foot tower height to a 100 foot tower height involves a 10% increase in overall system cost, but it can produce as much as 29% more power.


There are two basic types of towers: self-supporting (free standing) and guyed (or anchored). Most home wind power systems use a guyed tower. Guyed towers, which are the least expensive, can consist of lattice sections, pipe, or tubing (depending on the design), and supporting guy wires. They are easier to install than self-supporting towers. However, because the guy radius must be one-half to three-quarters of the tower height, guyed towers require enough space to accommodate them. Although tilt-down towers are more expensive, they offer the consumer an easy way to perform maintenance on smaller light-weight turbines, usually 5 kW or less.
Tilt-down towers can also be lowered to the ground during hazardous weather such as hurricanes. Aluminum towers are prone to cracking and should be avoided. Most turbine manufacturers provide wind energy system packages that include towers.
Mounting turbines on rooftops is not recommended. All wind turbines vibrate and transmit the vibration to the structure on which they are mounted. This can lead to noise and structural problems with the building, and the rooftop can cause excessive turbulence that can shorten the life of the turbine.
Balance of System
The parts that you need in addition to the turbine and the tower, also known as the “balance of system” parts, will depend on your application.
Most manufacturers can provide you with a system package that includes all the parts you need for your application. For example, the parts required for a water pumping system will be much different than what you need for a residential application. The balance of system required will also depend on whether the system is grid-connected, stand-alone, or part of a hybrid system.
For a residential grid-connected application, the balance of system parts may include a controller, storage batteries, a power conditioning unit (inverter), and wiring. Some wind turbine controllers, inverters, or other electrical devices may be stamped by a recognized testing agency, like Underwriters Laboratories.
Stand-Alone Systems
Stand-alone systems (systems not connected to the utility grid) require batteries to store excess power generated for use when the wind is calm. They also need a charge controller to keep the batteries from overcharging. Deep-cycle batteries, such as those used for golf carts, can discharge and recharge 80% of their capacity hundreds of times, which makes them a good option for remote renewable energy systems. Automotive batteries are shallow-cycle batteries and should not be used in renewable energy systems because of their short life in deep-cycling operations.
Small wind turbines generate direct current (DC) electricity. In very small systems, DC appliances operate directly off the batteries. If you want to use standard appliances that use conventional household alternating current (AC), you must install an inverter to convert DC electricity from the batteries to AC. Although the inverter slightly lowers the overall efficiency of the system, it allows the home to be wired for AC, a definite plus with lenders, electrical code officials, and future homebuyers.
For safety, batteries should be iso-lated from living areas and electronics because they contain corrosive and explosive substances. Lead-acid batteries also require protection from temperature extremes.
Grid-Connected Systems
In grid-connected systems, the only additional equipment required is a power conditioning unit (inverter) that makes the turbine output electrically compatible with the utility grid. Usually, batteries are not needed.

SA gets additional finance for clean technology projects

By
Oliver Gordon
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0


The $500-million which was endorsed for South Africa in October under the international Clean Technology Fund (CTF), has enabled the government to leverage about three times the amount of additional finance for clean technology projects.
“We have now got $1,6-billion that has been leveraged out of that [CTF], and it looks as if there can be more leveraged,” said Environmental Affairs DDG Joanne Yawitch on Thursday.
She further explained that once finance was “put on the table”, government could leverage further funds for projects with the potential for long-term greenhouse gas emission savings.
These funds came from international and local investors and allowed lines of credit to be established, which could then “facilitate things happening in a way that government budgets can interact with them”.
She stated that, in the short-term accessing or finding money was not the problem, “but accessing it in a way that is coherent and where we are able to understand what there is, and have a global picture on how we can use the money effectively”, was the challenge.
The CTF, is administered by the World Bank group, and South Africa presented its investment plan at a meeting in Washington DC in late October.
Engineering News previously reported that the South African plan included using CTF financing for:
• the reduction of the high capital costs associated with the construction and operation of Eskom’s proposed 100-MW concentrating solar power (CSP) project, planned for Upington, in the Northern Cape;
• the development of the first utility-scale wind power plant, consisting of a 100-MW Eskom wind farm in the Western Cape Province Wind Energy Facility;
• pioneering private-sector wind projects of a further 100 MW and creating a robust pipeline of large-scale wind projects;
• supporting municipalities and the private sector in the deployment of solar water heaters (SWHs), with a target of achieving 50% of the South African government goal of converting one-million households from electric geysers to SWHs over five years; and
• scaling up energy efficiency investments by 
catalysing the expansion of bank lending to the 
commercial and industrial sectors through lines 
of credit to commercial banks and addressing barriers to energy 
efficiency investments.
The CTF has also endorsed country investment plans in Egypt, the Middle East and North Africa region for a CSP project, Mexico, Morocco, the Philippines, Thailand, Turkey, and Vietnam.
Source…Engineering News

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