You've nailed the key issue: maximizing self-consumption is becoming increasingly vital due to grid saturation and declining solar export rates. Let's break down the pros and cons of each approach, east/west arrays vs. south-facing with batteries, and discuss the best strategy for you

East/West Arrays: Spreading Production
Pros



Better match to daily demand

East-facing panels produce power in the morning when demand is higher, and west-facing panels produce power in the afternoon/early evening. This helps avoid the mid-day production peak that often gets exported at low rates.

Reduced grid export

Less energy is sent to the grid during peak solar hours, potentially reducing the need for extensive grid upgrades or capacity limitations.

Potentially lower battery needs

The smoother power production curve might allow you to get away with a smaller battery system, or even no batteries at all depending on your consumption patterns.

More consistent production in cloudy conditions

Cloud cover can disproportionately affect south-facing arrays, but east/west arrays will still catch some sunlight throughout the day.

Better use of available roof space

In some cases, roofs aren't ideally suited for south-facing arrays, and an east/west orientation provides a more efficient way to utilize the entire surface.

Cons



Lower peak production

You won't achieve the same peak power output as a south-facing array. This might be a disadvantage if you have high energy demands at specific times (e.g., EV charging in the evening).

More complex design and installation

East/west arrays require more wiring, potentially increasing installation costs.

Potentially higher overall array size

To achieve the same total energy production over the day as a south-facing array, you might need a slightly larger east/west array.

South-Facing Arrays with Batteries: Peak Production + Storage Pros



Maximum energy production

South-facing arrays produce the most energy overall, capturing the sun's direct rays for the longest duration. This is great for regions with high solar irradiance.

Simple and cost-effective installation (historically)

South-facing arrays are typically easier and cheaper to install due to their straightforward design. (Though east/west installation complexity is decreasing).

Battery optimization

Batteries can store the excess energy produced during the day and discharge it in the evening when demand is high, further reducing grid dependence.

Cons



High initial cost

Batteries are expensive, significantly increasing the overall system cost.

Battery degradation

Batteries degrade over time, reducing their capacity and lifespan. You'll need to factor in replacement costs.

Round-trip efficiency loss

There's some energy loss when charging and discharging batteries (typically 10-15%), so you're not getting 100% of the stored energy back.

Mid-day overproduction

You'll likely be exporting a significant amount of energy to the grid during peak solar hours (mid-day), which may not be financially rewarding.

Which Approach is Right for You?

To determine the best approach, consider these factors:1. Your Energy Consumption Profile



When do you use the most energy? Morning, afternoon, evening, or a mix? If your usage is heavily weighted towards mornings and evenings, east/west could be ideal. How much energy do you use overall? High energy consumption generally favors a larger system, potentially including batteries. What are your specific appliances and their energy usage? Consider major energy users like AC, EVs, pool pumps, etc.2. Your Roof Characteristics



Orientation

Is your roof well-suited for south-facing panels?

Pitch

What is the angle of your roof? A lower pitch favors south facing panels.

Shading

Are there trees or other obstructions that might shade your panels? East/west configurations can be more resilient to shading.

Available space

How much roof space do you have for solar panels?3.

Local Utility Rates and Incentives



Net metering

What are the rates you receive for exporting excess solar power to the grid? If rates are low, maximizing self-consumption becomes even more critical. Also, consider NEM changes; you may be 'locked in' with great terms, or soon to be forced into the new paradigm.

Time-of-use rates

Does your utility offer time-of-use rates? This could make batteries more attractive if you can charge them during off-peak hours and discharge them during peak hours.

Rebates and incentives

Are there any rebates or incentives for solar panels or batteries?4.

Budget



Batteries are a significant investment. Be realistic about your budget and consider the long-term costs, including battery replacement.

Recommendation



Start with a detailed energy audit

Track your energy consumption over several days or weeks to understand your usage patterns.

Get multiple quotes from qualified solar installers

Discuss your goals and concerns with several installers and get their recommendations for system design.

Run simulations

Ask the installers to run simulations of different array orientations and battery sizes to estimate your energy production, self-consumption, and cost savings.

Consider a hybrid approach

In some cases, a combination of east/west and south-facing panels might be the best solution. For example, you could have a south-facing array for maximum energy production and a small east/west array to supplement your morning and evening demand.

Future-proof your system

Choose a system that can be easily expanded in the future if your energy needs change or if battery technology improves.

Consider an EV

If you are considering an EV, this will change all calculations.

In summary



If self-consumption is the primary goal and your energy usage is spread throughout the day

East/west arrays are likely a better choice, especially if you can minimize or eliminate the need for batteries.

If you have high energy demands, a south-facing roof, and can afford batteries: South-facing arrays with batteries can provide maximum energy production and energy independence.By carefully considering these factors, you can design a solar system that meets your specific needs and maximizes your self-consumption while minimizing your reliance on the grid. Good luck! Flag for review