If you've got an old, broken, space-eating gas lawn mower, you may be interested in resurrecting it and converting it into an eco-friendly solar charged model, provided you don't mind having it look a little Frankenstein.

This how-to walks you through the process of modifying a mower as well as creating the solar panel/charging station that provides the power. The mower does take a while to charge up (40 hours by the authors calculations, assuming a half-charged battery), but since most lawns don't require mowings of any greater frequency than that (or anywhere near that, one would hope), the solar solution seems like a perfect fit for the task.

The author provides a lot of detail, including a couple of schematics and a parts and costs table. The final price tag was $699, with the bulk of the cost going towards the motor ($312), solar panel ($120) and battery ($90).

Enviroscaping to Conserve Energy is an interesting guide on maximizing your home's energy efficiency by modifying various aspects of its immediate environment, or "Microclimate".

A microclimate is any small, local area within which the effects of weather are both relatively uniform and easily modified. Microclimate modification involves the best use of structural and landscape design elements to maximize or limit sunlight, shade and air movement. Structural modifications involve the design of the house and associated construction (walkways, fences, patios). Landscape modifications (enviroscaping) involve the use of plants to further increase or decrease the impact of sun and wind upon the local environment.

This site, which applies mostly to homes in hot weather climates such as Florida, offers a lot of interesting ways that a home owner can creatively reduce energy usage. Some of the suggestions apply to potential home builders, such as home orientation (a house is more energy efficient if it is oriented with the long axis running east-west), however the majority of the tips apply to existing residences.

There are many examples of "enviroscaping" strategies on the site, such as optimal tree placement for maximum shading, tree type (In winter, the sun is low in the southern sky. Southern exposures of a home in north and central Florida can receive free benefits of passive solar heating, provided that deciduous trees are used along the southern exposures. Deciduous trees shed their leaves in the fall, and are bare during the coldest months of the year.), fencing options (fences vary in amount of air circulation), shrub and vine placement along walls, increasing air conditioner efficiency and much more.

Link: Enviroscaping to Conserve Energy: a Guide to Microclimate Modification

Wind energy expert Paul Gipe has posted his thoughts on the Mag-Wind Verticle Wind Turbine (previously). Essentially, Paul deems this device everything but a dream:

Ok, let's take another approach. Mag-Wind says its wind turbine will produce 5 kW at a rated speed of 28 mph (12.5 m/s). To produce that much power at that wind speed it would need to be 281% efficient! Yee ha. That's some windmill. Modern wind turbines, at best, can deliver 40% of the energy in the wind at any specific wind speed. This turbine has a specific rotor loading of 3,360 W/m² of rotor area. Let's compare that to the over rated AirX. The AirX is somewhat smaller so we won't compare actual production, just rotor loading. Remember, the AirX doesn't even deliver what is promised. The specific rotor load for the AirX is about 400 W/m². The Mag-Wind claims to produce from its rotor almost ten times more power than the AirX which can't even meet its performance claims. Ouch. I've never seen such outlandish claims before-and I've seen a lot of them.

Link: Wind-Works.org

Via TreeHugger

Sunlight Direct's hybrid solar lighting system is an interesting new technology that essentially pipes sunlight into buildings via fibre optics. The system makes use of a GPS aware light collector unit that sits on a building's roof. The unit utilizes GPS along with an onboard processor to orient the light collector to within .1 degrees of the sun to maximize efficiency. The system monitors a room's natural light intensity via photosensors and, during cloudy periods, compensates by increasing the traditional fluorescent or incandescent lighting output.

Here's a YouTube video of the product in action.

Since 30% of electricity used in the US is for lighting (the number grows to 45% in retail), the product would theoretically have a huge potential market, especially commercially. The commercial version will light about 1000 square feet at a cost of about $10,000. That may sound expensive, but that's really only because that's a lot of money. However, if the (hard to believe) claims in the video of retailers seeing a 40% boost in sales when using natural lighting is true, then the $10,000 is largely irrelevant when viewed over the long term. According to the video, the company plans on launching a residential unit in 2008. No word on pricing...

Here's an interview with Duncan Earl, CEO of Sunlight Direct, that's also worth a look.

Instructables has a very thorough howto on building your own wind generator. According to the author, most of the materials can be found in junk piles or purchased at local hardware stores. The site lists parts and tools very well, but is, unfortunately, a little light on construction pictures. Nevertheless, this looks like a fun (and useful) project. The windmills can also be purchased from Vela Creations. Assembled or barebones parts-only kits are available here.

From the site:

The Chispito Wind Generator is a 100W machine. It outputs 14volts at 280 rpm, so it starts putting power into your batteries in low wind speeds (7-10mph). It makes a perfect addition to an existing solar, or other alternative energy, home system. On its own, it will power lights, radio, and conservative use of appliances such as computer, satellite, blender, drill, etc.

It's interesting to see smaller companies attempting to build/improve wind power systems instead of waiting for some of the larger players in the industry to offer products at more affordable price points. Some of the offerings out there are more than a little pricey and would take many years to produce a postive ROI.

Via Digg

According to Google, toilets account for anywhere between 20 to 40 percent of household water consumption. Given that we waste clean, otherwise drinkable water flushing our toilets, it should come as no surprise that many people harvest rainwater for toilets and other household purposes where potable water isn't necessary.

The author of this howto walks us through the setup of a rainwater-to-toilet system, while sharing his reasons for doing so:

While it doesn't come close to making up for our gas-guzzling, high-consuming lifestyles, rain harvesting does have a positive impact on our environment. Domestic potable water collection requires effort, energy, and chemicals for purification and transport...
Your house is an "impermeable surface". Rain would otherwise hit the ground where your house is and soak into the underground water table or enter a natural stream. Instead, rainfall from the roofs of many urban homes is tied into the sewer system. During periods of heavy rain, this storm surge from houses, parking lots, and streets into the sewer system can max out treatment capacity, causing raw sewage to flow out untreated into waterways. Harvesting some of this storm surge can reduce peak demands on our water treatment facilities.
Besides the more important environmental issues, most of us in urban areas pay for domestic potable water. I have calculated that each flush of the rainwater toilet (1.6 gallons) saves me just over 1 cent. Costing less than $100 to install, this system will pay for itself over the years.
Also, I have the satisfaction of a small level of self-sufficiency from an urban lifestyle otherwise dependant on society for survival.
The guide covers the details of rainwater collection, a formula for calculating your harvest potential, detailed pictures of the entire setup (including how to mesh the rainwater system to standard toilet plumbing via selector valve, enabling the toilet to run off of either system) as well as a breakdown of parts and costs for the project.