Design the system around the loads you actually use.
A dependable off-grid system starts with the house, not a box of equipment. Doug Mycko helps Big Island customers size solar panels, battery storage, inverter capacity and generator backup around real electrical loads, daily energy use and the way the home will actually operate.
Every major component affects the others.
An off-grid system is not simply a panel count or a battery size. Solar production, overnight energy use, inverter power, motor starting loads, generator charging and battery capacity all have to work together.
Electrical loads
Refrigeration, pumps, lighting, appliances, air conditioning, water heating, tools, EV charging and other loads determine both energy consumption and peak power requirements.
Solar array
The array must produce enough energy during available sun hours to run daytime loads and put the energy used overnight back into the batteries.
Battery storage
Battery capacity should reflect overnight use, expected depth of discharge, reserve capacity and how much autonomy the home needs during poor weather.
Inverter capacity
The inverter must support normal simultaneous loads as well as short-duration startup demands from pumps, compressors and other motor loads.
Charge control
PV voltage, current, string configuration and charge-controller capacity have to match the array and battery system.
Generator backup
A properly planned generator can carry loads and recharge batteries during extended poor weather without being unnecessarily oversized.
Plan before buying equipment.
The best time to make sizing decisions is before equipment is purchased. Start with the appliances and loads you expect to operate, then build the solar system around them.
- Daily and overnight energy use
- Largest simultaneous loads
- Pumps and other motor-starting loads
- Air-conditioning requirements
- Battery reserve goals
- Available space for the PV array
- Generator size and charging strategy
Expansion should solve the actual limitation.
If an existing system runs out of power, the answer is not automatically more batteries. The limitation might be insufficient PV production, inverter capacity, battery storage, charging capacity or simply a load that the original system was never designed to support.
Doug can help determine where the limitation actually is before equipment is added.
Solar TroubleshootingFrom electrical loads to a complete system.
List the loads
Identify what must run, its wattage or amperage, how long it operates and whether it has a significant startup surge.
Calculate energy
Estimate daytime and overnight consumption so battery storage and daily solar production are based on energy, not guesswork.
Size the equipment
Match the PV array, batteries, inverter and charging equipment to the load profile and the way the property will be used.
Plan backup power
Choose a generator and charging strategy that can support the system when solar conditions are poor or unusually heavy loads occur.
A system in Hawaiʻi still has to be designed for the specific site.
Hawaiʻi Island has very different solar conditions from one location to another. Cloud cover, rainfall, elevation, shading, roof or ground-mount orientation and the customer's electrical habits all affect the design. A system should be planned for the property where it will actually operate rather than from a generic package size alone.
Build the rest of the system around the design.
Start with what you need the house to do.
For a useful design conversation, make a list of the major electrical loads, pumps, air conditioners, appliances and anything else that will use substantial power. Doug can work from there.