Under the current NEM 3.0 billing method, we recommend that the monthly power generation of solar panels should be at least 1.5 times higher than the average electricity consumption. Here are the reasons:

1. Whenever the power generated by solar panels is insufficient and the batteries are also depleted, you will need to purchase electricity from the grid. Under the NEM 3.0 billing method, for every unit of electricity you buy from the grid, you need to supply four units back to even out. Therefore, your system must have a certain surplus.
2. Due to changes in sunlight angles and the rainy season, the same solar panel system may produce 50% more electricity in summer than in winter. However, the electricity consumption in winter and summer might be similar.

Therefore, when your solar panel system’s power generation is at its lowest in winter, it should still be higher than or equal to your average electricity consumption. Otherwise, you would need to buy a significant amount of electricity from the grid in winter. Despite having a solar panel system installed, you would still face high electricity bills.

Given these practical issues, we generally recommend ensuring that the average power generation of solar panels is at least 1.5 times higher than the average electricity consumption.

However, this is just the minimum recommendation.

In fact, we always advise maximizing the system size within your financial capacity because:

1. Under the same system, the price difference between different power scales is not particularly significant. Upgrading from an 8kw to a 12kw system increases the power by 50%, but the cost might only increase by 20%.
2. The Republican Party supports traditional energy sources. Therefore, if the Republicans win the election at the end of the year, it’s almost certain that the current 30% solar tax credit will be abolished or significantly reduced. Additionally, the import tariffs on solar equipment will likely be greatly increased, further raising costs. To take advantage of the 30% tax credit, it’s crucial to plan early. If you decide to install in the latter half of the year, the actual installation might be delayed until after the new president takes office in 2025, by which time this significant incentive may no longer be available.
3. With the proliferation of electric vehicles and smart appliances, household electricity consumption will double in the future. If you consider expanding your old system then, you’ll not only have to pay for additional solar panels but also incur thousands of dollars in design, application, and inspection fees, as well as at least a few thousand dollars in hardware costs for adding new conduits and upgrading inverters. Moreover, extra labor costs for removing old wiring to connect new equipment would amount to at least a few thousand dollars. The final upgrade cost will be several times higher than the incremental power costs if you had done it all at once. This is a lesson shared with us by many clients who needed to upgrade their old systems.
4. A very important point: Maximum power allows for complete energy independence. You can enjoy a lifestyle of “wasteful” energy usage without worrying about energy expenses at home, a quality of life that is entirely different from one of penny-pinching.