£1500 is a good chunk to start a business with, I'm a strong believer that any business can be started purely by elbow grease alone, cash can make things easier but it can also be a curse as you often end up spending it on the wrong things! If you have a very limited reserves to begin with then the pressure is on to get the minimal together and start getting money in to fund further expansion. Plus if you can work hard and get the skeleton together there's more chance of getting investment in the future.
How many times have you watched the Dragons Den and the business owner has said "I've so far invested £100,000 because i'm in my full time job, and i've so far made £1000 sales" - normally followed quickly by "i'm out" all around. Whereas if they say "I've been trading for 3 months, i've only made £1000, but i've worked hard on a small budget, got regular clients, proven that there's a market and need to expand quickly to capture that market"... there's normally a lot more interest at the table.
Ideas on GREEN initiatives...
Your friend could think about advising businesses on how to improve their environmental policies, and maybe help implement them.
There was someone on ebay a while back (canada i think) who was advertising plans to make Solar heaters for about £150... the plans were only £5. After looking at them your friend could look at making a similar heater (providing they were a good quality).
Paper recycling - you would need an old washing machine! Turn paper to pulp, you could use banana skins and allsorts, create some nice textured papers and flog them especially to arts and crafts people.
You could also see if there's any innovative green products in the states, europe or australia. They might be eager to get into the UK market and offer you good deals to import a couple to sell, or simply order them in as you sell them...
Not sure how feasible the ideas are, but finding innovative green products abroad and import them would be a sure winner if you found the right product and marketed it well!
Jen