PROFESSOR CELESTINO RUIVO: Yes, yes, very nicely.

REPORTER: Smells nice.

PROFESSOR CELESTINO RUIVO: Oh, magnifico... and will taste good.

REPORTER: How many people will you serve today with food? How many?

Celestino Ruivo is Portugal's solar crusader. Right now, this professor of engineering is sacrificing his weekend to cook lunch for a pack of hungry scouts.

PROFESSOR CELESTINO RUIVO: And the rice is ready. Bread. Here we have sardines, Portuguese sardines. Very nice. Here, the same apparatus with a cake. Coffee is boiling, Here, we have chicken.

REPORTER: Oh, apples?

But what's special about the menu is not the food, it's how it's cooked.

The professor-cum-chef shows me how to make a quick oven.

PROFESSOR CELESTINO RUIVO: It's good example of solar cooking. I'm a fanatic.

Simple, certainly, but solar is renewable and, in Portugal these days that's what it's all about.

PROFESSOR ANTONIA SA DE COSTA, PORTUGUESE ASSOCIATION OF RENEWABLE ENERGIES: Look, we can do it, we can keep importing coal and even from South Africa, from Australia, or import gas, but we'll be always dependent from these sources and dependent on the price and since, let's put it this way, it's God has given to the Arabs the oil and they have given to Portuguese the wind, the sun and the waves. For instance, for Australia, Australia I think you have... I have been there - you have the sun, you have the waves, concerning the water, the rain. You know, it's not that much, but anyway you have areas where it is quite rainy and can be used. But I don't know Australia, but sun and wave they have for sure, and why not use them?

PROFESSOR MANUEL COLLARES: It's connected to the tank, to the water.

Companies like his are taking advantage of European concerns about climate change.

PROFESSOR MANUEL COLARES: Climatic changes are today perceived in Europe as a very, very serious threat. Climatic change is due to the burning of fossil fuels so the European Commission, the European Union, is much more committed now than it was in the past to renewable energies and to energy efficiency. So that is influencing the policies. And of course it influences the policies in Portugal too.

But Portugal is going much further than the EU target of 20% of renewables by 2020. Here at Serpa, in the dry inland, is the second biggest solar array in the world. Engineer Jaime Toucas is proudly showing it off to a group of businessmen. They're all interested in using alternative energies in their companies.

This site may look large, but a new facility that is planned nearby will be five times this size. It has yet to begin construction, but outside the town of Moura, land has already been allocated to build the largest solar farm in the world. Like many small towns, its young people have drifted away to the city in search of work. But the people of Moura are hoping that solar power will revitalise their sleepy town.

JOSE MARIA POS DE MINA, MAYOR (Translation): In this shire alone we have 900 people registered as unemployed. This project, just in building the network, will create over 100 temporary jobs. Once the factory is set up it will initially employ 115 people. We'll be setting up a laboratory and other attractions for investors. So we're aiming to create 1,000 to 1,200 jobs.

And the town gets more than just jobs - 2.5% of the revenue from renewable fuels goes straight to the local council.

DR MIGUEL BARRETO, DIRECTOR-GENERAL, MINISTRY OF ECONOMY AND INNOVATION: Today we have a good relationship between the populations and renewable energies - people accept and they want it in the sense of municipalities fight for having more renewable projects, which is quite an interesting perspective.

REPORTER: Could Australia do this?

Portugal receives more sun than anywhere else in Europe, but it's not relying on solar alone.

PROFESSOR ANTONIA SA DE COSTA: Producing energy is something that is like our food. You cannot select one type of food to do it with only from that type of foods, not only eggs, not only milk, not only meat, not only fish, not only potatoes. To have a good thing you have to have a mix, a balance, and the sources of electricity, there should be a balance because hydro has good things and bad thing, solar has good things and bad things, coal has good thing and bad things, so we have to have a mix.

Portugal is crisscrossed by rivers, so it's no surprise that hydro-electric power will be the foundation for Portugal's green revolution. This is the largest dam in the country and there are plans to build many more in the future. And as you drive up Portugal's northern coast, you can't miss a more recent source of energy wind turbines dotted all over the countryside, powered by strong winds blowing straight off the Atlantic Ocean. 80 metres high, with blades 45 metres long, they feed power into the national electricity grid.

DR MIGUEL BARRETO: We will have several thousand jobs created, new factories for windmills, and from the end of it, and a 70 million euro fund for innovation in renewable energies. So I think you start by pushing renewable energies and energy efficiency and in the end you create new economic activities and new economic clusters that can create jobs and can create innovation, and I think people are starting to understand the advantages of it.

On this wind farm alone, there are 37 windmills - or turbines - producing over 100 megawatts of electricity. At full capacity, they could power a town of up to 50,000 households.

MAN: Today is very good.

REPORTER: A lot of wind out there?

MAN: Yes, yes, yes. We can see some turbines are near 20 metres per second.

But the wind farms do have their critics.

MAN: Some people are happy, some people are not happy because they say the wind farms - the turbines make some noise, and the impact visual.

But perhaps the most innovative and exciting solution to Portugal's energy needs lies just offshore. This is the test unit for what will soon become a 'wave farm'. Portugal will be the first country to produce energy commercially from the power of the waves. It is the movement of these giant tubes, built by a Scottish engineering firm, that supplies the energy. The constant expansion and contraction, both up and down and sideways, pushes oil through a hydraulic system driving motors that supply power back to the shore. It's time to have a look inside.

ENGINEER: This is the intelligent part of the machine. Up here you've got a hydraulic ram. This is the main component, which takes the energy out of the ocean swell. Then there's hydraulic pipes, which takes this into a hydraulic motor at the bottom here, which, in turn, attaches to this electrical generator. Then all the electrical generators are linked together throughout the machine and an electrical cable runs back to shore. When it is in rough seas, this will be moving up and down and side to side quite vigorously, but that's the energy we're taking out of the ocean.

This unit is just about ready to be towed up to the testing grounds off northern Portugal, where the Atlantic swells roll in. Lisbon, the capital of Portugal. As in most other major cities these days, people are being asked to reduce their energy consumption and their waste. But here they've found a way of using garbage to help fuel their city. At the tip, they're turning trash into gas. They divided the tip into cells. As each cell fills, it is covered, and an access well fitted. As the solid waste decomposes, it gives off methane gas.

MAN: These gases are coming from the cells.

REPORTER: From the cells we just saw?

MAN: Where are the solid wastes. And then we can transform this biogas into electricity. You can see here this is the electromagnetic valve that controls each well and you can see this valve is opening 100%. That means these wells are producing a lot and a good biogas. I think it's marvellous. I think it's wonderful that we have waste in first of all we can use for anything, but we can use it to produce energy, to produce electricity, so wastes are useful if you can use in the right form.

PROFESSOR ANTONIA SA DE COSTA: It has been, and now is going under some discussion, but Portugal, we have a problem with nuclear energy. Nuclear energy only comes in XXXL size, it doesn't come in small or medium size, they go up to 3XLs and for Portuguese dimension, one nuclear power plant has a 1,600 megawatt power plant and this is too much.

PROFESSOR MANUEL COLLARES PEREIRA: Ah, this is a very good question because I think this will have a very, very positive impact. We will certainly be able to create new jobs. Um, we will create. So we will empower many companies in Portugal to have their own technology and then we can even export. In the future we can export all these technologies and these capacities to other countries. So the impact of this on the economy is in that sense quite large.

It's my last day in Portugal and I've been invited to lunch with Professor Ruivo, the solar chef extraordinaire.

PROFESSOR CELESTINO RUIVO: Very powerful this solar cooker. This is an antenna.

Before we eat, he can't help showing me his latest, and best, solar oven up on the roof.

PROFESSOR CELESTINO RUIVO: Very powerful! A lot of heat.

REPORTER: What would you cook in this?

PROFESSOR CELESTINO RUIVO: Everything, everything, everything.

REPORTER: Why is Portugal racing ahead of Australia in renewable energy?

PROFESSOR ANTONIA SA DE COSTA: We start first and Portugal is the turtle. Australia is the hare and when the hare starts to run it will catch the turtle. I think the hare is asleep and we're awake and go past. I'm not saying it's a bad thing being asleep because you can profit from the experience and mistakes of the others.

REPORTER: What do we have?

PROFESSOR CELESTINO RUIVO: Potatoes and diet fish, Bacalhau. In Portuguese we say 'bacalhau'.

REPORTER: Bacalhau. And this was cooked by the sun?

PROFESSOR CELESTINO RUIVO: By the sun in a solar cooker, in a solar cooker. No gas, no electricity, no wood.