Home improvement can pay for itself, and even put cash back in your pocket – if you’re putting your money in the right places.  Renovations that increase your home’s energy efficiency aren’t just nice for the environment, they can be economical as well.  The folks at One Block Off The Grid offer a great guide to help you sort out which upgrades make the most sense for your home.

The graphic highlights a range of improvements, both big and small, that will cut your utility bills while reducing your home’s environmental footprint.  Each project is marked with four key figures:  average annual savings, projected savings over a 20-year period, the amount of time for the project to pay for itself, and the cost of the renovation.

(click to view the full size image)

The handy illustration points out that in terms of financial investment, many of these home upgrades can offer a better payoff than traditional investments like stocks or CDs.  And depending where you live, incentives like rebates and tax breaks can make the renovation costs substantially cheaper.

These aren’t just long-term projects, either:  upgrades like low-flow showerheads and programmable thermostats can pay for themselves in less than a year, making them a good choice for renters as well as homeowners.  Larger scale renovations on the other hand, like a green roof or solar array, have the potential to save a homeowner tens of thousands of dollars over the years.

(via One Block Off The Grid)

A community swimming pool called the Richmond Plunge has just opened in Richmond, California, and it may be the most efficient swimming pool in the country. The Richmond Plunge has many efficient features: it’s heated by solar collectors, it’s entirely chlorine-free, and the building is powered by solar panels on the roof. The Plunge is a historic pool — it was first opened in 1926. Now, after ten years of renovation it has been reopened.

It’s a huge pool — it holds 324,000 gallons of water and measures 60 feet by 160 feet. The water is heated by being circulated through eighty Heliodyne Gobi solar collectors on the roof.

The pool also contains no chlorine. Instead, a saline solution is used, coupled with an ultraviolet disinfectant system. This means children and other swimmers can swim without goggles, and they will avoid the other health hazards of chlorine (which we detail in this recent article). The use of natural ventilation and the reduction of chloramines in the water will make swimming in the Plunge a healthy experience.

The pool also has an array of solar electric panels that produce 30 kilowatts for the building. This large, solar hot water heating system was installed by Sun Light & Power, a San Francisco/Bay Area solar installation company.

Link: Richmond Plunge

An Irish company, Surface Power, has launched what could be the most efficient solar hot water panel ever produced. The company says it plans to distribute its product internationally. The new solar panel was independently certified by TUV Rhineland. Their tests verified that when compared to other solar panels, Surface Power’s solar panel was in one case as much as 131% more efficient in the morning and evening, and 76% more efficient at midday.

Surface Power estimates that the product, which has undergone six years of development and testing, has the potential to reduce domestic and commercial hot water bills by up to 70% if insulation standards meet new building regulations.

“The market for the solar collector was worth in excess of one billion dollars  in 2008 and has grown by 300% since 1998. We received over 400 enquiries from the USA alone last month after the specifications were released during the Christmas period. We also expect the international home renovation market to be very strong during the next three years, as our collector is the only pre-packaged vacuum collector on the world market. This leads to quicker, simpler and cheaper installations,” said John Quinn, Surface’s founder.

Source: Renewable Energy World via Cleantechnica

I recently noted that Hawaii has enacted a law that requires all new homes to install solar water heaters. Eventually, Hawaii may have as many water heaters as Israel, where 90% of homes have solar water heaters installed. When viewed from above, the Jerusalem often glitters with the shine of the thousands of solar heaters that adorn rooftops.

These heaters were first installed when the country experienced a fuel supply crisis in the early 1950s. The government responded by severely restricting the times when water could be heated. Israelis in turn responded by purchasing huge quantities of solar water heaters. By 1983, 60% of the population heated their water with the sun. A law was eventually passed requiring the installation of solar water heaters.

In 2005, Spain became the second country (after Israel) to require solar water heaters. It also became the first country to require the installation of solar cells for electricity generation in new buildings.

In many climates, a solar heating system can provide a very high percentage (50% to 75%) of domestic hot water energy.

In many northern European countries, solar power is used not only to heat water, but also to provide 15 to 25% of home heating energy.

For more info about different solar water heating systems for the home, see the Solar Water Heating by Bob Ramlow.

The Proximity Hotel is proof that a hotel can be very green without sacrificing the comfort of its guests. The hotel is located in Greensboro, North Carolina, and it achieved a Gold LEED certification this year from the U.S. Green Building Council. The Proximity uses 36.5% less energy and 30% less water than a conventional hotel. It gets 60% of its hot water from 100 solar thermal panels on the roof. The hotel also boasts the first regenerative drive elevator, which recaptures energy as the elevator moves down.

^{Dennis Quaintance, Chief Design Officer of Proximity Hotel with the 100 solar panels atop the hotel.}

The guest rooms take advantage of abundant natural lighting with large energy-efficient “operable” windows that measure 7’4” square.

The hotel has a green, vegetated rooftop on the restaurant to reduce the “urban heat island effect.” In other words, the green roof reflects the heat, thus reducing the amount of energy needed for refrigeration and/or air conditioning. It also slows the rain runoff and insulates the rooftop, keeping the building cooler overall.

The hotel used building materials with recycled content. For example, reinforced steel contains 90% post consumer recycled content , sheetrock 100%, asphalt 25% and staircase steel 50%. Concrete contains 4% fly ash, the mineral residue left after the combustion of coal that is diverted from landfills.

During construction they restored 700 linear feet of stream by reducing erosion, planting local, adaptable plant species and rebuilding the buffers and banks. And 376 tons of boulders and 18 logs were used to maintain grade control, dissipate energy and assist in the creation and maintenance of riffles and pools.

The full list of the hotels’ green features can be found on this page.

Solar Water Heating is the first book I’ve seen that focuses solely on solar water heating. It’s a technique that’s been practiced since ancient times, but until now there’s been strangely few resources on the topic for a North American audience. The author, Bob Ramlow, examines state-of-the-art solar heating systems. He covers not only solar water heaters, but also solar water and space house heating systems and solar pool heating systems, including their advantages and disadvantages. Since people often get turned off by the up-front cost, the book focuses especially on the financial aspects of solar water or space heating systems, and shows that such systems can save significant costs in the long run.

It’s available from Amazon for $16.47.

A Canadian company, Pulsar Advanced Technologies, claims to have produced a water heater that uses microwave technology to heat water instantaneously. The company says: “The Vulcanus MK4 can heat water from 35 degrees Fahrenheit to 140 degrees Fahrenheit in seconds and can source multiple applications at once: showers, dishwasher, sink usages and more. The Vulcanus MK4 is the size of a stereo speaker with a sleek modern look, making it ideal for condos and apartments, while powerful enough to serve the needs of any size family.” Groovy Green has been tracking the progress of this product, and the latest update can be found here. Apparently the heater isn’t quite to market yet, the manufacturers are looking to be certified in the U.S. and Canada.

Takagi water heaters do not have tanks, instead they heat water instanteously using a gas burner. They are efficient and powerful — even the smallest heater, the Takagi T-KJr., can produces 180 gallons of hot water in an hour, but weighs only 30 pounds and is 20 inches high. They run on propane or natural gas.

Computer controlled electronic ignition allows the heater to operate without a pilot light and save up to 50% off utility costs. Prices range from $600-$1000. The heaters also have powered ventilation, computer-modulated gas flame for steady output temperatures and the industry’s best energy factor of 0.84

Takagi heaters can be used with solar preheated incoming water — only adding additional heat as needed to meet a set output temperature.

Available from: Tankless Water Heaters or Real Goods

Here are some advantages and disadvantages of tankless water heaters from the California Energy Commission.

Here’s a short new story on Takagi heaters: ABC News

Solar water heating works efficiently even in cloudy areas. Home Power Magazine recently ran an article that gives a simple overview of solar water heating systems (well, relatively simple).

In the article, they examine various popular systems that have proven themselves reliable.

Some systems are “open loop” (the domestic water itself is directly heated) and some are “closed loop” (a heat transfer fluid is heated by the collector and the heat is passed on to the domestic hot water by means of a heat exchanger). Some systems are “active,” using moving parts such as pumps and valves, and others are “passive,” using no mechanical or moving parts.

Apricus makes a unique solar hot water heater which is 30-40% more efficient than flat plate solar systems.

The secret to the performance is the use of cylindrical evacuated glass tubes to absorb the heat from the sun. Because the tubes are cylindrical, there is always a surface area that is perpendicular to the sun.

The tubes also house a vacuum between two layers of glass. Why a vacuum? A vacuum is an excellent insulator. The insulation properties are so good that while the inside of the tube may be 304°F (150°C), the outer tube is cold to touch. This means that solar tube water heaters can perform well even in cold weather when flat plate collectors perform poorly due to heat loss.

More information: Apricus