Part Two:THE SOLAR SCHOOLHOUSE:

Design Principles

Passive Solar Design• The structure itself is the collector and heat storage system• South facing windows are a form of passive solar collector called a

direct gain system– they collect solar heat. • Sunlight enters and is absorbed by surfaces, changing into heat. • Heat is transferred throughout the house without the use of fans or

pumps. • Each square foot of south facing window typically saves you a gallon

of heating oil over the winter heating season. • The building has no windows on the north or west sides, where heat

loss, not gain, occurs.

Storing Heat for Cold Nights• To avoid overheating the

building and store energy for nighttime use, thermal mass is required in the form of a concrete slab, masonry, tile, or water barrels.

• These absorb the sun's energy, warms, and reemits the energy later when the house is cooling.

• The slab under the Schoolhouse was insulated to prevent heat loss to the ground.

The Trombe or Vertical Mass Wall• Indirect solar heat gain, passive solar collector• No fans or pumps involved in the system• Located at the far left front of the building• Glazing looked onto concrete blocks painted black• Openings at the top and bottom allowed warm air to

circulate • The concrete block wall is superior storage

Energy Efficient Construction

Proper insulation of the walls and roof: R-25 to R-30 for walls and R-40 for roofs.

Windows R-3 or higher Houses with large amounts of

insulation are sometimes called superinsulated houses.

Air infiltration is stopped by tight house construction

Very tight construction may require use of an air-to-air heat exchanger

Comfortable Functionality

• The recycled post and beam construction allowed for a large open room without support partitions

• Perfect gathering place for classes, tour groups, or social events

• Allowed heat to circulate freely

Two photovoltaic cells sat in maximum direct sunshine (30+ year life)

50 kW-hr a month for lighting and some appliance use (1/10th use of typical U.S. home)

A Windcharger wind mill produced 100 watts of power (14 volts at 7 amps DC) when the wind exceeded 20 mph, beginning at 8-10 mph.

OFF GRID: Electricity charged 12 volt rechargeable batteries

DC-AC inverter brought the voltage up to 120 volts AC

NET MTERING: synchronous inverter connects to utility power.

Excess electricity is sold to the utility.

At night, electricity bought from utility.

Meter runs backwards and forwards

Solar Electricity from Photovoltaic Cells and Wind: Resilience from Off Grid vs Grid Options

Solar Hot Water

A passive batch solar water heater was made from a 30 gallon metal water heater painted black set in an insulated box with a transparent cover.

Reflective foil on the sides and back of the tank directed all the incoming sun's rays to the blackened tank.

This was a warm weather system.

As cold water was pumped from the ground, its temperature was raised from 50 degrees F to around 110 degrees F

Stored for night time use.

Our first wind generator experience at the AEEC places the grid/off-grid issue in historical perspective. This was a Jacobs Generator from the late 1920s or early 1930s (see http://telosnet.com/ wind/20th.html).

The Wind Generator

The Jacobs’ Generator

1920's Jacobs brothers built wind energy system to electrify their remote Montana ranch.

Mid-1920's, Jacobs Wind Electric Company

Moved to Minneapolis in the early 1930's.

Manufactured thousands of wind electric plants which provided power to isolated farms and ranches. (http:// www.windturbine.net/history.htm)

People Power

It was an unforgettable moment in the mid-1970s when, the tall wind tower having been assembled by fifty Ramapo College students on the ground, they heaved together on long ropes to pull the tower upright. After the tower was secured, the Jacobs Generator was moved into position by a crane. Two faculty then climbed the tower and prepared the generator for operation.

The Modern Windmill

After two decades of service, the Jacobs was replaced by a modern lightweight Whisper generator. The new machine could generate 1 kilowatt despite its much smaller size and it began generating at 7 mph breezes, unlike its heavy predecessor, giving it wider utility (http://www.electricalternatives.com/world_power_technologies.htm).

A Monument to Renewability

While the Whisper will be re-erected at the new RCSEC, the Jacobs will be a centerpiece sculpture in one of the gardens. Thus, the Jacobs will continue to tell its story about the grid and the history of alternative energy to future generations of learners as it has for the past thirty years.