[cma-l] Mains power where there ain't any!

[Two Lochs Radio]

If you could link it up to the wind coming from the studio that would be 
good!!

Seriously though, the practicality would depend on all sorts of factors - 
especially how windy your area is, whether there is an acceptable spot for 
the turbine, and of course how powerful your transmitter is.

If it's just a 25W one, or for a short term opertaion, then it would be 
feasible, but probably not with wind power alone - it simply doesn't blow 
reliably enough for a 24/7 supply unless hugely oversized. You would need 
substantial backup batteries to ride out the periods of calm or too strong 
wind, and ideally perhaps a complementary source such as solar. Even then 
this winter, for example, we had weeks of almost no wind and minimal sun, so 
anyone reliant on them would have been in a sticky position.

Of course, that is the big problem with wind power overall - it can never 
more than a relatively small part of the mix overall, and for every wind 
turbine you have, you need an alternative reliable source as a backup. The 
national output from wind farms throughout a large part of December was not 
much more than 1% of their advertised output! In spring of the same year 
wind generators had been paid huge subsidies for keeping their stations 
off-line because there was too much power on the market - boom or bust with 
wind!

I looked at the possibility of doing it for a low power relay once (25W) 
using an integrated lampost that can be bought pretty much off the shelf 
with a combination of solar and wind generators on top. They are advertised 
as offering up to 380W of *peak* power, but even in our location which is 
very favourable for wind it looked like this would have an average output 
closer to 30W and significant periods of outage. It was designed to run a 
77W lamp for 10 hours a day, so it would have been pushed to run the 
transmitter and ancilliaries for 24hours - we considered overnight shutdown 
as an option.

There is now another with a 750W rated output that might be more suitable 
for a 25W set up (bear in mind transmitters are not generally very efficient 
and with overheads and a link receiver you are likely to be looking at 50W 
consumption at least. As Ian said, poweering the gear from low supply 
voltages without unecessary up-down conversions could help efficiency. See 
http://www.scionpower.com/Site/sanya-hybrid-street-lamp. With the antenna on 
the same pole as well it could be a beautifully self-contained an elegant 
solution. No doubt it would qualify for various grants as well.

Of course in a remote spot you could possibly have a far more meaty wind 
turbine, but the maintenance and access provisions would be important.

Maybe overall when you are building a radio station it's bad enough having 
to allow for relatively infrequent power cuts, and you might be just adding 
one more worry, plus a long-term maintenance overhead, for little benefit 
unless the transmitter site has no real alternative source. Would be nice to 
see someone manage it though.

Alex


----- Original Message ----- 
From: claire penketh
To: studio at ravensoundradio.co.uk ; cma-l ; ian at transplan.uk.com
Sent: Friday, June 24, 2011 12:23 AM
Subject: Re: [cma-l] Mains power where there ain't any!


 What about a wind powered transmitter? Is that a possibility?


 Claire Penketh
Better to have given it a go than never to have tried at all