R
Renewable Energy
Energy harnessed from natural sources that are continually replenished on a short time scale, the process of which releases minimal emissions into the atmosphere. In other words, the ingredients are often ubiquitous, such as water, wind, sunlight, tides and waves.
http://en.wikipedia.org/wiki/Renewable_energy
Return of Investment (ROI)
In finance, rate of return (ROR), also known as return on investment (ROI), rate of profit or sometimes just return, is the ratio of money gained or lost (whether realized or unrealized) on an investment relative to the amount of money invested. The amount of money gained or lost may be referred to as interest, profit/loss, gain/loss, or net income/loss. The money invested may be referred to as the asset, capital, principal, or the cost basis of the investment. ROI is usually expressed as a percentage rather than a fraction.
