How to Size a Solar System for High Summer Energy Use

When the temperatures rise and air conditioners roar, so does your electric bill.

Pool pumps, EV charging, and long sunny days mean one thing: higher summer energy usage. Knowing how to size a solar system to meet this demand isn't just smart—it can help you reduce bills, boost home value, and enjoy year-round energy efficiency.

Here, we break down how to calculate the size of a solar system to match your peak energy needs in July and August, including pool heating, AC usage, and EV charging.

 Whether you're designing a new system or expanding your current setup, this post is your blueprint for optimal solar panel performance.

Why Is Summer Energy Usage So High?

Southern California summers are hot. That means more electricity to cool your home, run your pool equipment, and charge your electric vehicle (EV) after long drives. This high electricity use can push your bills way up—unless your solar panels are sized to match.

During these months, your solar system must cover peak energy usage for air conditioning systems that run for hours a day, pool heaters and pumps working overtime, and EV charging, especially during evening or weekend use.

Understanding what drives your energy consumption is the first step to designing the right solar panel system.

How to Calculate the Size You Need

To size your solar system, you'll first need to review your energy bills—especially for July and August. Look at daily kWh use, peak times of day, and any seasonal spikes. You want to size your system to cover your average daily summer use, plus any added demand from pool heating or new appliances.

Many homeowners underestimate the amount of energy their AC and pool equipment pull. A professional solar installer can help calculate your solar generation needs using real-time consumption data.

What Is a Typical Solar Panel System Size?

Most California homes install a 5–8 kW system, which produces roughly 20–35 kWh/day in summer. But if your energy usage is higher—due to pools, hot climate demands, or EV charging—you might need a 10–12 kW system.

When designing your system, factors that affect how many solar panels you need include panel wattage and efficiency, roof orientation and shading, summer and winter sun hours, and system losses such as inverter inefficiency or wiring issues.

To maximize your solar, aim for a system to meet 100% of your electricity needs during peak summer.

How Many Solar Panels Do You Need to Power Your AC?

Air conditioning is often the largest energy consumer in summer. A typical 3-ton AC uses about 3.5–5 kW/hour, running 6–8 hours daily in extreme heat.

That translates to 20–40 kWh/day of usage during the hottest months.

To offset that, you’d need a 7–10 kW solar panel system, assuming good sun exposure and optimal panel size. That’s roughly 20–25 panels, depending on panel output.

Sizing for Pool Heating and Pump Use

Pool systems are another energy-intensive feature, especially when heating is involved. Pumps alone can consume 2–3 kWh/day, and electric heaters significantly more.

If you’re using solar pool heating, sizing depends on the pool surface area and whether you want to heat in shoulder seasons. Most systems recommend a collector area equal to 50–100% of the pool size.

For PV offset, factor in the pool pump energy, any automation controls, and seasonal operating schedules.

Check out our solar panel cleaning service to keep performance high in dusty months.

Planning for EV Charging Demand

An EV adds serious load. A daily roundtrip commute of 30–40 miles requires 8–12 kWh/day, depending on the model.

Level 2 chargers at home draw 7.2 kW, usually used in the evening. To size your solar system properly, consider:

• Shifting EV charging to midday when solar panels generate
• Using a battery system to store excess solar energy
• Increasing solar system size to offset both home and vehicle usage

Need help with battery storage? New Day Solar offers full system design and installation.

Should You Oversize Your System?

In many cases—yes. Oversizing ensures the system can handle future additions like a second EV or heat pump, time-of-use rate plans where midday production is key, and slight panel degradation over time.

An oversized solar panel system can also generate enough power to qualify for net metering credits or charge a home battery.

What Is the Right Solar System Design?

Every home is different. A professional solar installer will tailor your system design based on roof space and direction, local weather and shading, and panel size and inverter match.

At New Day Solar, we use trusted brands like Enphase and QCells to deliver dependable, long-term performance.

What Happens If You Undersize?

If your system is too small, you’ll:

• Pull more electricity from the grid
• Miss out on energy savings
• Be less protected from rate increases

That’s why it’s critical to size your solar system based on actual summer usage. Even better: let our team at New Day Solar inspect and optimize your current system before expanding.

What About Batteries?

Adding solar batteries lets you store excess solar energy during the day and use it at night, during blackouts, or for EV charging.

It also reduces time-of-use penalty rates.

Explore battery systems like Tesla Powerwall, Franklin Home, or NeoVolta on our battery page.

Work With a Local Southern California Solar Company

When sizing a solar panel system, local experience matters. At New Day Solar we have installed systems across Murrieta, Temecula, and Southern California for over 20 years.

They specialize in:

• Full system design and permits
• Solar battery integration
• Solar panel maintenance and upgrades

Get personalized advice on the system you need to power your home in the heat of summer.

Ready to Size Your Solar System?

Sizing a solar system for high summer energy use isn’t just about managing costs—it’s about preparing your home for future energy demands.

Whether you want to keep your AC running without fear of a high bill, power your pool all summer long, or charge your EV sustainably, the right solar panel system can make it happen. Contact us today for a free assessment and custom proposal. Let our award-winning team help you get the most out of every ray of sunshine.