What is the risk in selling a covered call at a strike price considerably higher than the stock price at the time I wrote the call? It seems that the only risk is less profit if the call is exercised.
Whenever you write a covered call, first ensure that you would be happy to lose the stock at the net effective sale price (NESP = call strike price plus call premium). If NESP does not provide the anticipated profit when you first acquired the stock, you probably should not write the call. Writing a far out-of-the-money call (or, as you stated, a “call at a strike price considerably higher than the stock price") may offer very little premium. Ask yourself if the net premium, after the transaction costs, is enough to justify the transaction.
A ground rule employed by many covered call writers is that the potential return, if the stock is called, should be about twice the risk-free (Treasury bill) rate. As an example, if a 60-day Treasury yields 5% per annum, a two-month covered call write should produce an annualized 10% return.
This guideline also states that the return created by the covered write should equal at least the risk-rate if the stock remains static. Another guideline regarding premium is that the downside protection gained by call writing should equal at least 3% of the stock's current market price. There is also the risk that the stock could drop significantly, or to zero.