Hello,

I'm new here so i will give an short introduction of me regarding to solar.
I'm an electronics Engineer and build four solar boats in total.
I participated in the frisian solar challenge twice. The first time was with my highschool in 2006 and the second time was with my own team,bobsolar team, in 2008. In 2008 we won in our class with our catemaran. 6 solar panels with 1Kwh lead gell optima batteries. Here some pictures for the eye.

Wow, very nice. What speeds can you achieve in full sun?

Is can do about 12 km/h with a 1200Watt BLDC motor pod in the water. However we didn't optimize the screw of the motor so there is a lot to gain in speed. Here a movie when we tested the boat last year.

http://www.youtube.com/watch?v=TxSt7K4VX1s

In another class the boats are doing higher speeds of about 16 km/h and the fastest goes 24 km/h but that is with gallium arsenide solar cells.

The solar panels we used were provided by the organization and are Sharp 175 W peak power panels. we had six of them.
We used MSTE MPPT for each panel one.

This year i'm in another team the furia one team and we are goeing to participate in the dutch open solar challenge in june of this year.

Here another movie of the "klunnen" part of the race.

http://www.youtube.com/watch?v=nYf4sDIKIT8

There are two dams in the route of the race so you have to lift your boat out of the water with 4/5 persons.
Our Boat is with solar pannel (100KG) 235 kg.

hey i just had a look at the videos, it looks like you are going much faster than 12Km/hr.
The "klunnen" part is very funny lol.
One of the teams nearly hit the motor pod in the ground.

How much did the other team spend to purchase the gallium arsenide array? Have you got pictures of that?
Can you use lithium polymer batteries instead of lead acids?

It is the boat of TU delft, they also participate in the WSC and i think these panels are Nuna 2 left overs. I do not know the amount of money they spend on those cells but i guess the cost over 100.000 euro's.



http://www.nuonsolarteam.nl/nuna4/geschiedenis#

For the battery part; you also can use Lipo but last year we didn't have the budget for it. You can carrie arount 1Kwh on batteries in your boat so ~25 kg of Lead acid ~6 kg of Lipo.

I saw the nuna solar car, it looked amazing. I was at the WSC in 2007.
I heard they spent close to one million USD on their cells.

That is i think in the right price catagory. But the cells on the boat above are left overs/spare cells with some hot spots and even then they are very expensive.
wubbo ockels(astronaut) is a connected to the TU and he has connections with the NASA/ESA space institutes. So they have as i think easy acces to those cells.

I head those cells have close to 40% efficiency.

I think that 40% is a bit to much more lik around 28% Triple junction gallium arsenide

http://www.spectrolab.com/DataSheets/TNJCell/utj3.pdf