The average cost of a roof mounted wind turbine is around Â£2,000 which will also need to be maintained (The Energy Savings Trust estimate that this could cost Â£100 to Â£200 per year). Find our list of roof mounted turbine manufacturers here.
You can substitute vegetable oil, cup for cup, for shortening. Using oil versus shortening will change the texture of baked goods. The shortening, being a solid fat, will add more air to the batter when beaten in, giving the end product more of a cakey structure rather than the more dense structure oil will give. Ultimate Baking Secrets Revealed.
Shortening is another name for the fat used in making pastry, bread or in this case a cake. You may use Crisco, or other shortening, real butter, or some margarines. You will need to be aware of the amount of water in any given margarine and do not use light or diet margarine since they contain too much water and will change the texture of your cake.