PV Gap

Joy Said:

would a gym powered by the exercise machines be feasible?

We Answered:

Nowhere near.

A human metabolises roughly 2000 kcal food a day; that's around 8000 kJ or 2 1/4 kW hr. That won't get you very far.

Nancy Said:

how can i build a solar bicycle?

We Answered:

You would probably be better off buying an electric bicycle or scooter. Those are available for purchase from a manufacturer and charge from a household outlet. You can then have solar panels installed on your house to offset the electric energy used by your scooter.

This would be far more efficient than installing solar panels on a bike. Any way you look at it, the air drag will be pretty bad and the solar panels won't always be facing the sun. With panels installed on your house, you can optimize their location and offset your household electric power usage along with that of your scooter. So, I say you should ditch the solar idea and just build an electric bike (which will certainly be a task in itself).

First you will need to find an appropriate electric motor. The selection of your motor will dictate what motor control circuit (motor drive) you will use. You will also have to interface some sort of throttle with the motor control circuit such that you can control your speed. Also, you will need a battery pack and some way to charge it. Finally, an on/off disconnect switch along with various mechanical components would likely be needed in order to retrofit the bike. And if you have time, a gauge that indicates how much juice is left in the batteries would be nice.

So, there you go. That is one general solution to try. Have fun.

Ida Said:

I want to convert my bicycle to an eletric assisted bicycle. What is the easiest and cheapest option?

We Answered:

First of all forget solar- the amount of power you'd get from a 1m square panel would take about three months to charge an ebike enough to ride for a day. Most ebikes run on 24v or 36v systems; a 12AH battery pack will generally run them for a range of about 50km.

You can buy the components to build an ebike separately but it may be just as cheap to buy the whole thing. If you want to DIY as a minimum you'll need:

1. Wheel/motor unit- the motor is built into the hub. 250W is power-assist only, would not get you up a hill on its own. 500W will handle an incline of 10 degrees.

2. Speed controller.

3. Battery pack. NiMH will last longer an get more range for the weight, lead-acid is cheaper. NiMH are good for ~1000 charge cycles, lead acid is good for ~300 cycles.

In Canada you can get the components and complete bikes from Daymak (http://www.daymak.com). They ship anywhere in North America.

Judy Said:

How could I make 900 watts of power?

We Answered:

The way I see it :
900 watts of power is not a joke and you can not get it free while having fun.
"bicycle powered generator can only produce about 200 watts." What sort of generator is this? Which is bigger, the generator or the bicycle ?

Jane Said:

"Green" Bicycle Race -- Need Sponsor?

We Answered:

I don't know anything specific, but you could talk to:

local bike shops
big bike companies and ask (without giving details first) for contact info for their local rep
clothing shops
battery retail outlets
check the net for companies that might have equipment that could be used.

Don't be afraid to think out of the box for sponsorship... If you have a route planned, think about businesses on the route. Think about green oriented companies.
Think about prosperous companies that aren't terribly green that might want to put some cash into getting their name associated with something eco-friendly.
Find specific examples of companies that have product that could be used and talk to them.

I helped a local (asian) company work out a sponsorship deal for an overseas racing team.

The company had some requirements for them that might be applied to your situation as well.

If anyone is going to give out sponsorship dollars or free gear or whatever, they are going to want to get something back for their efforts.

Think what you can provide them:
Having a capable pro photographer helps boatloads! If he sucks, you will get nothing. If he can't show a portfolio (and a relevant one at that), you will get nothing.

Think of how you can get media attention for your event:
Talk to local papers and local community magazines and get some plans for having solid details (ie a written agreement to place an article in their published material of a certain length with specific mention of sponsors).

Get as much planned out in advance as possible. Get the route planned. The approximate date and time. Prizes. Photographers names and websites. Find out what permits you need. Find out costs. Plan the number of volunteers required. Plan the emergency services. Plan checkpoints (water, tools, pumps, energy bars...)

Set up a blog for the event itself. Make it organized and neat.

It's going to be a lot of work, but if it's worth it to you, you could make it happen.

Right there are enough ideas that you could grab your local phone book and build a list of probably a hundred phone numbers or more to call. Google would probably give you 30 or 40 email addresses.