North Kingstown High School

Racing Through a Renewable Energy Resources Unit with Richard Hartman

Students in Richard Hartman's C-hour science class are studying about renewable energy resources. While many young adults are working from a textbook or completing tedious laboratory experiments, these high school students are hard at work in their solar and wind powered classroom, participating in a "virtual" solar car race across the country.
It began when Mr. Hartman worked with the students to accomplish quite a novel task--designing and building a system that will use renewable resources to power their classroom. Now that this project has reached its advanced stages, the classroom is lit with six 35 watt D.C. floodlights connected to four deep cycle batteries. The classroom also has an inverter for connecting this system to various A.C. applications. Currently, these batteries are being charged by a wind powered generator on a post outside the classroom. With winds at 28 mph, the generator can produce as much as 400 watts of energy; however, the average wind speed they have observed is around 10 mph. At this rate, and with speeds generally beginning to peak right around noon, the wind has successfully provided their lighting needs for the entire day.

The Wind Generator is mounted on a power pole placed outside the classroom by Narragansett Electric.

Our Wind Generator will produce 400 watts when the wind blows 28 mph. It starts turning at wind speeds of 5 mph and higher. The average wind speed in RI is 10 mph. So far, the wind generator alone produces enough power to recharge the batteries.
Jason is working in front of the classroom overhead projector which requires 650 watts of AC power. The picture illustrates that some areas in the classroom are adequately lighted with the 12 volt flood lights.
Some of the wind generator monitoring and control components were placed inside the box. We located the brake for the wind generator, its 40 amp breaker and a shunt for the wind generator amp meter in the box. When we no longer want the generator to charge the battery, the brake is a single pole double throw toggle switch which connects the generator positive and negative output leads together.
The batteries are 6 volt deep cycle lead acid batteries. We have four of them hooked up for a 12 volt system. Each battery is rated at 225 amp-hours, so with two twelve volt banks, we have 450 amp-hours of battery capacity. To prolong battery life, they should be recharged before they have been discharged to 40 - 50%.
The batteries have been located outside to reduce the hazard of a battery explosion. When batteries approach full charge, electrolytic action generates hydrogen gas on the negative plates and oxygen gas on the positive plates. Hydrogen is explosive at concentrations of 4 to 8 %. The battery box is located at the base of the power pole to reduce transmission loss for a 12 volt system.
During the virtual solar car race, student-teams of two to four students accessed weather forecasts on the internet on one of four computers in the room. They were required to find the weather at their starting location every morning, predict how far they would travel to their noon location, then record both the noon location and the predicted weather.
Once students have checked the weather at their morning start location, predicted their rate of travel from 8-12am, estimated their noon location, then recorded the noon location along with their prediction of the weather at noon, I accept their race forms. Later I check their predictions against the actual weather on USA Today - Weather. I also check their travel distances using Yahoo's Point to Point Driving Directions to confirm their virtual noon location and to determine their virtual ending location for the day at 4pm.
During our visit to their "off the grid" classroom, Mr. Hartman's students were engaged in the fourth day of a solar car race exercise. The race started in North Kingstown and will end at the Golden Gate Bridge in California. With the help of the Internet, students were selecting target destinations, referencing weather forecasts for that area, and projecting mileage based on the predicted weather conditions.

Rates of solar energy collection fluctuate with various weather conditions that the students were using to determine their projected mileage for that day. These included cloud cover and temperature as well as wind vector (speed and direction). Forecast conditions and mileage predictions are handed in on a worksheet; the worksheet is then handed back for the next class period with actual conditions that dictate actual ending locations for that day, taking into account random accidents.
To study the weather in Earth Science we did a virtual solar car race cross country from NK High School to the Golden Gate Bridge in San Francisco. The students had to decide what routes to take based on a long term weather forecast. Some went north, others south and some made a direct approach. Some found and used satellite photos of the US showing current cloud cover and their movements. Steve is filling out his daily race form to indicate what routes he will be traveling in the short term.
Jason has obtained the existing weather at his morning start location and is estimating where his team will be at noon.
"Our team's 'car' only made it to Scranton, PA on the first day....We are starting in Denver, CO today," said Robyn from the yellow team. Students working with her on this team explained that the weather was cloudy on prior days, reducing the daily distance "traveled". Other teams were in Forth Collins, Co; Augusta, GA; St. Louis, MO; Checotah, OK; and Souix Falls, SD.
We still have to mount our 75 watt PV panel. Jason on the right side is designing a mount to put the panel on the pole facing south and inclined 41 degrees = Latitude.
In the future, Mr. Hartman intends to power the classroom's computers using the renewable energy resources collected by their system. As well, students are helping Mr. Hartman to install a 75 watt photovoltaic panel to supplement wind power for charging the batteries.
Using the internet to study weather is different from studying the material from a textbook. The virtual solar car race gets points across in an active way that results in a lot of one-on-one teaching within a class of twelve students.

updated 1998 June 8

	Our Wind Generator will produce 400 watts when the wind blows 28 mph. It starts turning at wind speeds of 5 mph and higher. The average wind speed in RI is 10 mph. So far, the wind generator alone produces enough power to recharge the batteries.
	Jason is working in front of the classroom overhead projector which requires 650 watts of AC power. The picture illustrates that some areas in the classroom are adequately lighted with the 12 volt flood lights.
	Some of the wind generator monitoring and control components were placed inside the box. We located the brake for the wind generator, its 40 amp breaker and a shunt for the wind generator amp meter in the box. When we no longer want the generator to charge the battery, the brake is a single pole double throw toggle switch which connects the generator positive and negative output leads together.
	The batteries are 6 volt deep cycle lead acid batteries. We have four of them hooked up for a 12 volt system. Each battery is rated at 225 amp-hours, so with two twelve volt banks, we have 450 amp-hours of battery capacity. To prolong battery life, they should be recharged before they have been discharged to 40 - 50%.
	The batteries have been located outside to reduce the hazard of a battery explosion. When batteries approach full charge, electrolytic action generates hydrogen gas on the negative plates and oxygen gas on the positive plates. Hydrogen is explosive at concentrations of 4 to 8 %. The battery box is located at the base of the power pole to reduce transmission loss for a 12 volt system.
	During the virtual solar car race, student-teams of two to four students accessed weather forecasts on the internet on one of four computers in the room. They were required to find the weather at their starting location every morning, predict how far they would travel to their noon location, then record both the noon location and the predicted weather.
	Once students have checked the weather at their morning start location, predicted their rate of travel from 8-12am, estimated their noon location, then recorded the noon location along with their prediction of the weather at noon, I accept their race forms. Later I check their predictions against the actual weather on USA Today - Weather. I also check their travel distances using Yahoo's Point to Point Driving Directions to confirm their virtual noon location and to determine their virtual ending location for the day at 4pm.
During our visit to their "off the grid" classroom, Mr. Hartman's students were engaged in the fourth day of a solar car race exercise. The race started in North Kingstown and will end at the Golden Gate Bridge in California. With the help of the Internet, students were selecting target destinations, referencing weather forecasts for that area, and projecting mileage based on the predicted weather conditions. Rates of solar energy collection fluctuate with various weather conditions that the students were using to determine their projected mileage for that day. These included cloud cover and temperature as well as wind vector (speed and direction). Forecast conditions and mileage predictions are handed in on a worksheet; the worksheet is then handed back for the next class period with actual conditions that dictate actual ending locations for that day, taking into account random accidents.
	To study the weather in Earth Science we did a virtual solar car race cross country from NK High School to the Golden Gate Bridge in San Francisco. The students had to decide what routes to take based on a long term weather forecast. Some went north, others south and some made a direct approach. Some found and used satellite photos of the US showing current cloud cover and their movements. Steve is filling out his daily race form to indicate what routes he will be traveling in the short term.
	Jason has obtained the existing weather at his morning start location and is estimating where his team will be at noon.
"Our team's 'car' only made it to Scranton, PA on the first day....We are starting in Denver, CO today," said Robyn from the yellow team. Students working with her on this team explained that the weather was cloudy on prior days, reducing the daily distance "traveled". Other teams were in Forth Collins, Co; Augusta, GA; St. Louis, MO; Checotah, OK; and Souix Falls, SD.
	We still have to mount our 75 watt PV panel. Jason on the right side is designing a mount to put the panel on the pole facing south and inclined 41 degrees = Latitude.
In the future, Mr. Hartman intends to power the classroom's computers using the renewable energy resources collected by their system. As well, students are helping Mr. Hartman to install a 75 watt photovoltaic panel to supplement wind power for charging the batteries.
	Using the internet to study weather is different from studying the material from a textbook. The virtual solar car race gets points across in an active way that results in a lot of one-on-one teaching within a class of twelve students.