The quote physicists often say when asked about nuclear fusion is that ‘commercial fusion is 40 years away, but we’ve been saying that for 40 years’. Two main types of fusion are in development – ‘tokamaks’ like JET and ITER that use magnets to fuse hydrogen in a torus of plasma and those that shoot high powered lasers at pellets of hydrogen a few times a second, making bursts of energy.
Neither process is currently producing more energy than is put in to start the reaction but there have been some developments in laser technology that may help the latter approach. The EU has recently decided to fund a new high energy laser research project to build a working reactor. Laser fusion may ‘ignite’ and provide energy before the magnetic fusion research reaches the same point but the pulses of laser energy need to come much faster and more efficiently for this to be economically viable. Without considerable funding, the technological challenges of getting hydrogen to fuse will be insurmountable. However, fusion offers a real hope in the long term (30 years+) of providing clean energy.