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Hydropower: water wheels and large-scale dams



With India set to fast-track almost 100 new hydropower plants, and as the Federal Energy Regulatory Commission in America prepares to issue further hydroelectric projects across the country, Joseph Iddison takes a closer look at producing electricity from flowing water.

The process of generating electricity from a hydropower generator involves passing natural water flow through a generator to produce kinetic energy, which is then converted into electricity.

Producing electricity from water has long been an established form of energy generation. Ancient Greek farmers used water wheels to grind wheat into flour. Placed in a river, the water wheel picks up flowing water in buckets located around it, with the kinetic energy of the flowing river turning the wheel. This mechanical energy runs the mill.

In the 1700s, hydropower was broadly used for milling of lumber and grain and for pumping irrigation water.

Being able to harness the power possibilities of water saw hydropower play an important part in the Industrial Revolution. It gave impetus to the growth of the machine-shop industries in the early 19th century. Although the steam engine had already been developed, coal was scarce and difficult to ship. However, by the middle of the century, the opening of the canals enabled coal to be distributed and transported, meaning it became a more sought-after resource.

Nevertheless, hydropower remained a useful source of energy, mainly due to its controllability and being naturally replenished. Developments in technology saw the first hydroelectric power plant built – at Niagara Falls in 1879. In 1881, street lamps in the city of Niagara Falls being powered by the electricity generated from hydropower. Just a year later, the world’s first hydroelectric power plant became operational in the US – in Appleton, Wisconsin. The station produced 12.5 kilowatts of power and used direct-current technology.

More than 200 hydropower stations were in operation around the world before the 20th century. Such was the productivity of hydropower that, in 1940, it accounted for 40% of America’s electricity generation.

Hydropower in recent years

Nowadays, hydropower plants use alternating current and typically consist of three parts: an electric plant where the electricity is produced; a dam that can be opened or closed to control water flow; and a reservoir where water can be stored.

The water behind the dam flows through an intake and pushes against blades in a turbine, causing them to turn. The turbine then spins a generator to produce electricity. The amount of electricity that can be generated depends on how much water moves through the system as well as the height at which the water drops. This electricity can then be transported over long-distance electric line.

Contemporary hydroelectric systems vary in size and application. Micro-hydroelectric plants are the smallest types of hydroelectric systems and can generate between 1 kilowatt and 1 megawatt of power. They are ideal for powering smaller services such as processing machines and small farms, and often use rivers as their water source. Large hydroelectric systems can produce electricity to power communities and cities.

At present, hydroelectric power provides almost a fifth of the world’s electricity.

Modern day usage and benefits

As one of the most cost-effective resources, hydropower is the cheapest way to generate electricity today. Apart from the construction cost of the dam and plant (for large-scale generators), the energy source is free, controllable and naturally replenished. And, according to the British Hydro Association, modern hydro generators can convert over 90% of the energy in the available water into electricity – more efficient than any other form of renewable generation.

Another advantage to hydropower is the fact that it is readily available; the flow of water through the turbines to produce electricity can be accessed and managed on demand. There is also the benefit of community prospects that some reservoirs offer, such as swimming and other leisure activities for the public.

Disadvantages and criticism

Some critics have argued that hydropower plants and dams as a technique of mitigating climate change are in fact more harmful to the planet than we are lead to believe.

In a study published in Mitigation and Adaptation Strategies for Global Change, Philip Fearnside estimated that, in 1990, the Curuá-Una dam in Pará, Brazil, produced more than three-and-a-half times the greenhouse gases than what would have been produced by generating the same amount of electricity from oil.

Furthermore, hydropower generators, particularly when large-scale (and therefore constructing a dam and reservoir), are often criticised for altering river ecosystems, killing fish and affecting water quality. Indeed, initial plants were often less considerate of local wildlife and social effects, mainly due to the environmental criteria for the build being far less rigorous.

Currently, however, hydro developments are subject to stringent environmental standards. Before a project can be developed, it must go through a process that examines its impact on both the environment and on local communities. Water flow, water quality, water shed, management, fish passage, habitat protection, as well as the welfare and lifestyle of the local communities are also taken into consideration.

Perhaps the main reason for using and investing in hydro, though, is because of its role as a provider of baseload power (the minimum amount of electricity needed) – something that wind and solar cannot do. This means that there is a crucial place for hydro projects as part of a renewable energy mix, as we seek to find alternative sources of power and energy to the current dominant, polluting options.

Further reading:

What happens when clean energy gets dirty

Brazil hydropower potential linked to Amazon conservation

The diversity of renewables

Majority of EU member states support clean energy: infographic analysis

The Guide to Limitless Clean Energy 2013

Joseph Iddison is a master’s student at the University of Leicester. Having graduated from the same institution in July 2013 in English, Joseph will start the global environmental change course in September.


New Zealand to Switch to Fully Renewable Energy by 2035



renewable energy policy
Shutterstock Licensed Photo - By Eviart /

New Zealand’s prime minister-elect Jacinda Ardern is already taking steps towards reducing the country’s carbon footprint. She signed a coalition deal with NZ First in October, aiming to generate 100% of the country’s energy from renewable sources by 2035.

New Zealand is already one of the greenest countries in the world, sourcing over 80% of its energy for its 4.7 million people from renewable resources like hydroelectric, geothermal and wind. The majority of its electricity comes from hydro-power, which generated 60% of the country’s energy in 2016. Last winter, renewable generation peaked at 93%.

Now, Ardern is taking on the challenge of eliminating New Zealand’s remaining use of fossil fuels. One of the biggest obstacles will be filling in the gap left by hydropower sources during dry conditions. When lake levels drop, the country relies on gas and coal to provide energy. Eliminating fossil fuels will require finding an alternative source to avoid spikes in energy costs during droughts.

Business NZ’s executive director John Carnegie told Bloomberg he believes Ardern needs to balance her goals with affordability, stating, “It’s completely appropriate to have a focus on reducing carbon emissions, but there needs to be an open and transparent public conversation about the policies and how they are delivered.”

The coalition deal outlined a few steps towards achieving this, including investing more in solar, which currently only provides 0.1% of the country’s energy. Ardern’s plans also include switching the electricity grid to renewable energy, investing more funds into rail transport, and switching all government vehicles to green fuel within a decade.

Zero net emissions by 2050

Beyond powering the country’s electricity grid with 100% green energy, Ardern also wants to reach zero net emissions by 2050. This ambitious goal is very much in line with her focus on climate change throughout the course of her campaign. Environmental issues were one of her top priorities from the start, which increased her appeal with young voters and helped her become one of the youngest world leaders at only 37.

Reaching zero net emissions would require overcoming challenging issues like eliminating fossil fuels in vehicles. Ardern hasn’t outlined a plan for reaching this goal, but has suggested creating an independent commission to aid in the transition to a lower carbon economy.

She also set a goal of doubling the number of trees the country plants per year to 100 million, a goal she says is “absolutely achievable” using land that is marginal for farming animals.

Greenpeace New Zealand climate and energy campaigner Amanda Larsson believes that phasing out fossil fuels should be a priority for the new prime minister. She says that in order to reach zero net emissions, Ardern “must prioritize closing down coal, putting a moratorium on new fossil fuel plants, building more wind infrastructure, and opening the playing field for household and community solar.”

A worldwide shift to renewable energy

Addressing climate change is becoming more of a priority around the world and many governments are assessing how they can reduce their reliance on fossil fuels and switch to environmentally-friendly energy sources. Sustainable energy is becoming an increasingly profitable industry, giving companies more of an incentive to invest.

Ardern isn’t alone in her climate concerns, as other prominent world leaders like Justin Trudeau and Emmanuel Macron have made renewable energy a focus of their campaigns. She isn’t the first to set ambitious goals, either. Sweden and Norway share New Zealand’s goal of net zero emissions by 2045 and 2030, respectively.

Scotland already sources more than half of its electricity from renewable sources and aims to fully transition by 2020, while France announced plans in September to stop fossil fuel production by 2040. This would make it the first country to do so, and the first to end the sale of gasoline and diesel vehicles.

Many parts of the world still rely heavily on coal, but if these countries are successful in phasing out fossil fuels and transitioning to renewable resources, it could serve as a turning point. As other world leaders see that switching to sustainable energy is possible – and profitable – it could be the start of a worldwide shift towards environmentally-friendly energy.


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5 Easy Things You Can Do to Make Your Home More Sustainable




sustainable homes
Shutterstock Licensed Photot - By Diyana Dimitrova

Increasing your home’s energy efficiency is one of the smartest moves you can make as a homeowner. It will lower your bills, increase the resale value of your property, and help minimize our planet’s fast-approaching climate crisis. While major home retrofits can seem daunting, there are plenty of quick and cost-effective ways to start reducing your carbon footprint today. Here are five easy projects to make your home more sustainable.

1. Weather stripping

If you’re looking to make your home more energy efficient, an energy audit is a highly recommended first step. This will reveal where your home is lacking in regards to sustainability suggests the best plan of attack.

Some form of weather stripping is nearly always advised because it is so easy and inexpensive yet can yield such transformative results. The audit will provide information about air leaks which you can couple with your own knowledge of your home’s ventilation needs to develop a strategic plan.

Make sure you choose the appropriate type of weather stripping for each location in your home. Areas that receive a lot of wear and tear, like popular doorways, are best served by slightly more expensive vinyl or metal options. Immobile cracks or infrequently opened windows can be treated with inexpensive foams or caulking. Depending on the age and quality of your home, the resulting energy savings can be as much as 20 percent.

2. Programmable thermostats

Programmable thermostats

Shutterstock Licensed Photo – By Olivier Le Moal

Programmable thermostats have tremendous potential to save money and minimize unnecessary energy usage. About 45 percent of a home’s energy is earmarked for heating and cooling needs with a large fraction of that wasted on unoccupied spaces. Programmable thermostats can automatically lower the heat overnight or shut off the air conditioning when you go to work.

Every degree Fahrenheit you lower the thermostat equates to 1 percent less energy use, which amounts to considerable savings over the course of a year. When used correctly, programmable thermostats reduce heating and cooling bills by 10 to 30 percent. Of course, the same result can be achieved by manually adjusting your thermostats to coincide with your activities, just make sure you remember to do it!

3. Low-flow water hardware

With the current focus on carbon emissions and climate change, we typically equate environmental stability to lower energy use, but fresh water shortage is an equal threat. Installing low-flow hardware for toilets and showers, particularly in drought prone areas, is an inexpensive and easy way to cut water consumption by 50 percent and save as much as $145 per year.

Older toilets use up to 6 gallons of water per flush, the equivalent of an astounding 20.1 gallons per person each day. This makes them the biggest consumer of indoor water. New low-flow toilets are standardized at 1.6 gallons per flush and can save more than 20,000 gallons a year in a 4-member household.

Similarly, low-flow shower heads can decrease water consumption by 40 percent or more while also lowering water heating bills and reducing CO2 emissions. Unlike early versions, new low-flow models are equipped with excellent pressure technology so your shower will be no less satisfying.

4. Energy efficient light bulbs

An average household dedicates about 5 percent of its energy use to lighting, but this value is dropping thanks to new lighting technology. Incandescent bulbs are quickly becoming a thing of the past. These inefficient light sources give off 90 percent of their energy as heat which is not only impractical from a lighting standpoint, but also raises energy bills even further during hot weather.

New LED and compact fluorescent options are far more efficient and longer lasting. Though the upfront costs are higher, the long term environmental and financial benefits are well worth it. Energy efficient light bulbs use as much as 80 percent less energy than traditional incandescent and last 3 to 25 times longer producing savings of about $6 per year per bulb.

5. Installing solar panels

Adding solar panels may not be the easiest, or least expensive, sustainability upgrade for your home, but it will certainly have the greatest impact on both your energy bills and your environmental footprint. Installing solar panels can run about $15,000 – $20,000 upfront, though a number of government incentives are bringing these numbers down. Alternatively, panels can also be leased for a much lower initial investment.

Once operational, a solar system saves about $600 per year over the course of its 25 to 30-year lifespan, and this figure will grow as energy prices rise. Solar installations require little to no maintenance and increase the value of your home.

From an environmental standpoint, the average five-kilowatt residential system can reduce household CO2 emissions by 15,000 pounds every year. Using your solar system to power an electric vehicle is the ultimate sustainable solution serving to reduce total CO2 emissions by as much as 70%!

These days, being environmentally responsible is the hallmark of a good global citizen and it need not require major sacrifices in regards to your lifestyle or your wallet. In fact, increasing your home’s sustainability is apt to make your residence more livable and save you money in the long run. The five projects listed here are just a few of the easy ways to reduce both your environmental footprint and your energy bills. So, give one or more of them a try; with a small budget and a little know-how, there is no reason you can’t start today.

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