S&P/ASX 200 Index (ASX: XJO) shares can be a great source of passive income because of their scale advantages. They generate enough profit to invest for growth and reward shareholders with dividends.

The two businesses I'll highlight are two of the most important in Australia because of what they provide for Australian households and businesses.

Given that ASX 200 shares have both defensive earnings and a track record of dividend growth, I'm calling them good buys for the long-term.

Coles Group Ltd (ASX: COL)

Coles is one of the two largest supermarket businesses in Australia. We all need to eat food, so the company has a high level of consistency to its earnings each quarter.

The business has been a very pleasing holding for passive income because of how its annual payout has been hiked every year since 2019, with that payout in 2019 being the first payout in its history as a separate entity from Wesfarmers Ltd (ASX: WES).

In the third quarter of FY25, the latest update from the business, it has continued delivering dividend growth. It said that total sales revenue increased 3.4% year over year to $10.4 billion, while supermarket sales grew 3.7% to $9.4 billion.

The forecasts on Commsec, suggest the company's annual dividend per share could grow to 75.6 cents in FY26, which is a grossed-up dividend yield of 5.2%, including franking credits. Then, there could be further growth in FY27 to 84 cents per share, which would be a grossed-up dividend yield of 5.8%, including franking credits.

I think the ASX 200 share's earnings can continue growing in the coming years as it benefits more from its new advanced warehouses and improvements in its online offering for customers because that's a growth area for Coles.

APA Group (ASX: APA)

APA is one of the largest energy businesses in Australia, with its huge gas pipeline network. The business transports half of the country's gas usage, which makes it an integral part of the economy and Australian life.

The ASX 200 share also has a number of other energy assets including wind farms, solar farms, electricity transmission cables, gas storage, gas processing and gas energy generation.

The business has grown its annual distribution every year for 20 years in a row, which is one of the best records on the ASX. Its cash flow is growing from a combination of its revenue being linked to inflation, as well as a steady expansion of its portfolio of assets.

Its FY25 distribution of 57 cents per security translates into a distribution yield of 6.6%, which I'd describe as a good level of income at a time when the RBA is reducing the cash rate.