The answer to 'what size generator installation do I need' is that the size of the generator you need will depend on the power requirements of your home. As a general rule, you'll want a generator that can provide at least 75-100% of your home's total electrical load, which includes things like your HVAC system, appliances, lights, and other electronics. This will ensure you have enough power to keep your essential systems running during an outage.
To determine the right size generator, you'll need to calculate your home's total electrical load. This involves adding up the wattage requirements of all the appliances and devices you want to power during an outage. Once you have that number, you can choose a generator with a rated output that meets or exceeds your needs. It's also a good idea to consult with a licensed electrician, as they can help you select the appropriate generator size and ensure it's properly installed to meet local codes and safety standards.