How to optimize your house battery income like a Pro

How to Track Your Home Battery Trading Income like a Pro

When I installed my home battery, I quickly realized that tracking the numbers properly is just as important as installing the battery itself.

If you use a dynamic energy provider like Frank Energie, your monthly invoice can include many different things at once: electricity usage, feed-in revenue, fixed costs, energy tax, network costs, VAT, expected amounts and corrections from previous months.

That can be confusing.

The most important lesson I learned is this:

Your total energy invoice amount is not the same as your battery trading income.

If you want to understand how much income you are making from trading, you need to separate the trading/feed-in income from the normal electricity costs you are paying.

The Problem with Energy Invoices

At first, I thought I could simply look at the final invoice amount from Frank Energie. But that does not give the correct picture.

The final invoice amount combines different items, such as:

• Electricity consumption

• Feed-in/trading revenue

• Fixed delivery costs

• Energy tax

• Network costs

• VAT

• Corrections from previous months

So if an invoice says I will receive money, that does not mean the full amount is trading income. And if an invoice says I need to pay something, that does not mean I had no trading income.

That is why I created a separate spreadsheet.

The Key Section: “Teruglevering”

On the Frank Energie invoices, the part I focus on for trading income is the section called:

Teruglevering

This is where the feed-in revenue is shown.

The important Dutch terms are:

Dutch term Meaning

Verwachte opbrengst Expected/provisional revenue

Werkelijke opbrengst Actual/final revenue

Betaald voor Amount already paid earlier, often used as a correction

The section called Stroom is different. That relates to electricity usage costs. I do not record those as income.

My Spreadsheet Structure

My income tab is simple. I use columns such as:

Column What it tracks

Date Invoice or settlement date

Customer / Platform Frank Energie

Income Type House battery trading / electricity feed-in

Description Month, kWh and invoice detail

Amount Received incl. VAT Gross amount

VAT Rate 21%

VAT Payable VAT included in the income

Net Income excl. VAT Actual income before VAT

Status Provisional, final actual or correction

Notes Explanation of the row

The goal is not to recreate the whole energy invoice. The goal is to capture the trading income clearly.

How I Avoid Double Counting

One confusing part is that Frank Energie may first show an expected amount and later show the actual result.

For example:

1. An invoice may show expected May income

2. A later invoice may show actual May income

3. The same later invoice may also reverse the earlier expected amount

If I record everything blindly, I could double count the income.

There are two ways to handle this.

Option 1: Only record actual income

This is the simplest method. You only record the Werkelijke opbrengst once the actual amount is known.

This is clean and safe, but it gives you less visibility over expected future income.

Option 2: Record provisional income and later corrections

This is more detailed. You record the Verwachte opbrengst first, then later record the actual amount and the correction.

This gives more transparency, but you need to be disciplined.

For my own spreadsheet, I use the second method because I want to see both expected and actual performance.

VAT: Keep It Separate

If I receive €121 including VAT, I do not treat the full €121 as income.

Part of that amount is VAT.

That is why I always split the amount into:

• Income including VAT

• VAT payable

• Net income excluding VAT

For example:

Income incl. VAT €190.47

VAT €33.06

Income excl. VAT €157.41

The net amount is the business income. The VAT is tracked separately for the VAT return.

My Simple Rule

This is the rule I follow:

Teruglevering / opbrengst = income
Stroom / kosten = usage cost
Notabedrag = invoice settlement amount, not trading income

This keeps the spreadsheet clean.

If I later want to track electricity costs, I do that in the expenses tab, not in the income tab.

Recommended Evidence to Save

I also keep evidence together with the spreadsheet. My folder includes:

• Frank Energie invoices

• Frank Energie app screenshots

• Battery setup screenshots

• Income spreadsheet

• VAT summary

• Profit summary

• Battery invoice

• Website articles linked to the battery project

What I Learned

The main thing I learned is that battery trading income is not difficult to track, but you need to read the invoice properly.

Do not use the final invoice amount as your income.
Do not mix usage costs with trading revenue.
Do not double count provisional and actual amounts.
Do separate VAT from income.

For my current invoices, the trading income recorded so far is:

€420.43 excluding VAT
€88.30 VAT
€508.73 including VAT

This is not profit yet. It is only trading income. Expenses, depreciation and other business costs are tracked separately.

Final Thoughts

If you use a home battery for smart trading, I recommend keeping a simple spreadsheet from the beginning.

It does not need to be complicated. It just needs to clearly separate:

• Trading income

• VAT

• Provisional amounts

• Actual amounts

• Corrections

• Usage costs

Once you separate those properly, your energy invoice becomes much easier to understand.

For me, the spreadsheet turned a confusing monthly invoice into a clear overview of what the battery trading activity is actually generating.

This article reflects my personal experience and is not tax or financial advice. Always check your own situation with an accountant or tax advisor if needed.