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Tidal energy: “potential to provide a source of clean green energy to the UK”



Matthew Woodhatch of Groundsure writes in their blog: “Tidal energy has the potential to provide a reliable and predictable source of clean green energy to the UK.” Republished with the kind permission of Groundsure.

The world’s tides are controlled by a complex but predictable relationship between the position of the moon and the sun producing a gravitational pull on the Earth’s oceans, combined with the effect of the wind and ocean currents. Therefore, sites which are prone to large and powerful tidal variations can potentially generate vast amounts of energy.

In July 2011, the UK government released its Renewable Energy Roadmap report setting out the future plans of the UK’s renewable energy strategy. Within the report, the section on marine energy highlighted a future £20m worth of government funding which would be put into new innovation and commissioning of marine energy testing facilities and the National Renewable Energy Centre (Na REC).  With a potential of 300MW being deployed to the grid by 2020, securing investment for projects and infrastructure, along with consultation on strategic environmental assessments and policy making, was a priority outcome of the report.

Similar to wind turbines, tidal turbines consist mainly of a tower structure connected to the sea floor with a number of turbines attached underneath the water. Electricity is generated as tidal water passes through the turbine blades causing them to rotate.  The energy generated is then sent through a system of substations and underwater cables and fed into the national grid.

Tidal turbines have the potential to mitigate some of the argued negative aspects of offshore wind turbines.  A prominent objection to offshore wind farms is the visual impact on the Seascape highlighted recently which the objections raised to the Navitus Bay wind farm located off the Dorset coast. Local Conservative MPs and councils expressed concern that the project would “industrialise” precious views and have “catastrophic” consequences for thousands of tourism-related jobs. As a result, government ministers have recently vetoed the application for the Navitus Bay wind farm development.

Where have we come from?

One of the first tidal turbine installations in the UK is the SeaGen S project located at Strangford Lough, Northern Ireland, which was installed in 2008. The SeaGen S 1.2MW devices consist of a twin axial-flow turbine supported on a structure which has the ability to raise the turbines out of the water for maintenance. Since it was commissioned the SeaGen S turbine has generated over 8GWH of electricity. It has since been upgraded with 20m rotors, increasing its output to 2MW, generating power for 2,000 homes.

Where are we going?

Swansea Tidal Lagoon

In June 2015, a tidal lagoon project to be located in Swansea Bay was granted development consent by the Secretary of State.  The Tidal Bay Lagoon project (TLP) consists of a large 9.5km breakwater creating an 11.5 km2 lagoon, with a sluice gate housing 26 turbines. When the tide rises, the sluice gates open, allowing water to pass through the turbines and into the lagoon.  As the tide falls the sluices are closed while the sea level drops, then the sluice gates are opened and water passes back through the turbines into the sea. This gives the potential to generate electricity at four intervals during a 24 hour period. The lagoon would generate 320MW of electricity 14 hours a day for 120 years, producing enough electricity to power 155,000 homes, equivalent to 90% of Swansea Bay’s domestic energy use8.

The lagoon will also incorporate water sports and leisure facilities, an amenity not just for local people but capable of hosting international sporting events. A visitor centre, educational facilities, art work, marine-culture and conservation programmes have all been included in the lagoon’s design, creating a unique tourist attraction in its own right.  A Chinese construction company has been contracted to the build the project, and a core aim is to create a significant local economic benefit to Swansea Bay. The project hopes to start construction in late 2016 and could be operational by the end of the decade.

Kepler Energy Project

Another tidal energy project which utilises a new revolutionary turbine design is the Kepler energy project being proposed in the Bristol Channel. Instead of using a lagoon and turbine gate system, Kepler Energy propose to use a Transverse Horizontal Axis Water Turbine (THAWT), designed loosely on the principles of old water wheels. The turbines are connected together to form a long fence-type structure with the turbines placed in-between connecting towers.  The new THAWT design enables a significant quantity of power to be generated, even in shallow, low velocity tidal zones.

The project proposes to construct a 1km turbine fence at an estimated cost of £143m and to be potentially operational by 2020/2110. The 1km turbine fence has the potential to generate an estimated 30MW, enough to power 30,000 UK homes a year. To increase the power output of one site, additional fences can be easily added to the fence structure which can generate extra power once installed.

Bigger picture?

The UK needs to meet its renewable energy goal of 15% of total production by 2020 and with significant objections raised to onshore and offshore wind farms, tidal energy farms could be the answer to meet the 5% expected shortfall in renewable energy production.  Given that the vast majority of a tidal energy farm’s infrastructure is located underwater, the visual impact on the landscape in comparison to wind turbine farms would be significantly less. Tidal power could be one answer to securing future renewable energy production whilst also preserving the natural appearance of our shore and coast line.

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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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Is Wood Burning Sustainable For Your Home?



sustainable wood burning ideas

Wood is a classic heat source, whether we think about people gathered around a campfire or wood stoves in old cabins, but is it a sustainable source of heat in modern society? The answer is an ambivalent one. In certain settings, wood heat is an ideal solution, but for the majority of homes, it isn’t especially suitable. So what’s the tipping point?

Wood heat is ideal for small homes on large properties, for individuals who can gather their own wood, and who have modern wood burning ovens. A green approach to wood heat is one of biofuel on the smallest of scales.

Is Biofuel Green?

One of the reasons that wood heat is a source of so much divide in the eco-friendly community is that it’s a renewable resource and renewable has become synonymous with green. What wood heat isn’t, though, is clean or healthy. It lets off a significant amount of carbon and particulates, and trees certainly don’t grow as quickly as it’s consumed for heat.

Of course, wood is a much less harmful source of heat than coal, but for scientists interested in developing green energy sources, it makes more sense to focus on solar and wind power. Why, then, would they invest in improved wood burning technology?

Homegrown Technology

Solar and wind technology are good large-scale energy solutions, but when it comes to small-space heating, wood has its own advantages. First, wood heat is in keeping with the DIY spirit of homesteaders and tiny house enthusiasts. These individuals are more likely to be driven to gather their own wood and live in small spaces that can be effectively heated as such.

Wood heat is also very effective on an individual scale because it requires very little infrastructure. Modern wood stoves made of steel rather than cast iron are built to EPA specifications, and the only additional necessary tools include a quality axe, somewhere to store the wood, and an appropriate covering to keep it dry. And all the wood can come from your own land.

Wood heat is also ideal for people living off the grid or in cold areas prone to frequent power outages, as it’s constantly reliable. Even if the power goes out, you know that you’ll be able to turn up the heat. That’s important if you live somewhere like Maine where the winters can get exceedingly cold. People have even successfully heated a 40’x34’ home with a single stove.

Benefits Of Biomass

The ultimate question regarding wood heat is whether any energy source that’s dangerous on the large scale is acceptable on a smaller one. For now, the best answer is that with a growing population and limited progress towards “pure” green energy, wood should remain a viable option, specifically because it’s used on a limited scale. Biomass heat is even included in the UK’s Renewable Heat Initiative and minor modifications can make it even more sustainable.

Wood stoves, when embraced in conjunction with pellet stoves, geothermal heating, and masonry heaters, all more efficient forms of sustainable heat, should be part of a modern energy strategy. Ultimately, we’re headed in the direction of diversified energy – all of it cleaner – and wood has a place in the big picture, serving small homes and off-the-grid structures, while solar, wind, and other large-scale initiatives fuel our cities.

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