I agree with Malcolm to the extent that a business may be a mixed business and consist of both trading and investment activities. If the income from solar and wind electricity production is purely a rent then this would be an investment activity, but if the income were reported as that of income into the farming business and reported in the same accounts, whether sole trader, partnership or Ltd Co, then it is merely an activity of that business. If the majority of the activity is that of conducting the trade (over 50%) then the whole of the business should receive the relief for IHT. Activity is largely a time based measure as opposed to just share of turnover or profit, the business needs to be looked at in the round.
The issue might be if the 3 acres had been separated from the farmland and that say the land and the income from the energy production was held and reported by say a separate entity, Ltd Co, then that element would have to be tested separately and then it would depend on whether this was merely a rent albeit linked to the energy production or the landowner and entity were say an active partner in the energy producing entity as the whether this activity is tested stand alone for BR, is it trading or investment.
Countrywide Tax and Trust Corp