Let's assume you have to pump 10,000 L of water per day, and you have a pump rated at 750 W that can pump 5,000 L per hour, and a storage tank that can hold four days worth of water (40,000 L). Your pump would have to work for two hours to meet the daily requirement, which would consume 1.5 kWh of electricity. That means your average deferrable load is 1.5 kWh/day. (HOMER lets you specify that value monthly.) The peak deferrable load is 0.75 kW because that's the power consumption of the pump -- you can't serve the deferrable load any faster than that. The storage capacity is 6 kWh, because that's how much electricity the pump would consume to fill the tank (8 hours at 750 W). If the pump can only run at its rated output, which is likely, then the minimum load ratio is 100%.