Southwestern Public Service Co rate plans compared

What does Southwestern Public Service cost at a normal month’s usage?

A household using 1,000 kWh a month pays about $1,244 a year on the cheapest of the 3 plans we can price here — Residential Heating Service - Rate 39 — and $1,697 on the priciest. Same house, same wires.

Annual cost at Southwestern Public Service by monthly usage
A month of	Cheapest, a year	On which plan	Priciest
500 kWh	$689	Residential Heating Service - Rate 39	$916
1,000 kWh	$1,244	Residential Heating Service - Rate 39	$1,697
2,000 kWh	$2,354	Residential Heating Service - Rate 39	$3,259

The same plan is cheapest at every level of use here, so the answer does not turn on how much you use. Estimates from the filed tariff, priced hour by hour on a household with central air — not a quote.

What does Southwestern Public Service Co's residential rate cost?

Southwestern Public Service Co files a single residential tariff, so there is no plan to choose between — everyone served here is on the same terms. That makes this page short on comparison and long on one question instead: what does that tariff actually do to a bill?

Priced hour by hour across a full year, a small apartment on this tariff comes to about $639 and a three-bedroom house with central air to about $1,132 — an effective 13.1¢ and 12.0¢ per kilowatt-hour once the fixed charge is spread across everything used.

With one plan and no hourly pricing, the only lever left is using less. Moving laundry or car charging to the middle of the night changes nothing here, which is worth knowing before you rearrange your evenings for no reason.

Expect the bill to swing with the weather rather than with anything you decide: the same house costs around $139 in July and $69 in February. Budget against the higher figure and the summer bill stops being a surprise.

How Southwestern Public Service compares across Texas

Run the same three-bedroom house with central air through its default plan at each of the 5 Texas utilities we cover, and Southwestern Public Service comes in 2nd cheapest at about $1,132 a year; the state median is $1,249. The range runs from $992 at City of San Antonio to $1,381 at Entergy Texas, and since the utility is set by the address, the part of that gap you can act on is the plan, not the company.

The other two households tell the same story in different sizes: a small apartment pays about $639 here against a state median of $707, and the same house with an electric car charging overnight about $1,510 against $1,717. Effective rate, fixed charge included, is 12.0¢ per kilowatt-hour for the family home.

Texas lets households choose their electricity supplier, so the supply half of this bill can be shopped separately. The figures above use the utility's own default supply price.

Every Texas utility we cover, priced for the same three households →

When are Southwestern Public Service’s peak hours?

Southwestern Public Service’s peak hours are noon–6pm, midnight–midnight, June–September. Everything outside those hours is off-peak.

At peak, Residential Heating Service TOU - Rate 39 charges 28.5¢ a kWh; off-peak it is 8.3¢ — 3.4× apart. These hours only matter on a time-of-use plan — the default plan, R (Residential Service) - Rate 1, charges one rate at every hour.

On Residential Heating Service TOU - Rate 39, every kilowatt-hour a day you move from noon to midnight is worth about $74 a year in the month the gap is widest — an electric car or a water heater on a timer is the kind of load that actually moves. When to charge an electric car →

Which plan would cost you least?

No bill upload, no sign-up. Tell us roughly what a month costs you and what runs on electricity — we price every plan against the same household and show you the gap.

Start from a household like yours

Then correct anything below that doesn’t match.

A typical monthly bill

$a month

A bill that size works out to about 1,225 kWh a month on R. If your bill shows a different number of kWh, switch to and use theirs — it is the more accurate of the two.

What else runs on electricity

Electric carcharged at home

Electric water heaterincluding heat pump

Central air conditioningsummer only

Electric heatheat pump or resistance

That adds up to 14,915 kWh a year. Compare it to the total on your bill and adjust until it’s close.

Same usage, different plan

$404a year

That is the gap between the cheapest plan you could be on — Residential Heating Service - Rate 39 — and the priciest. Not by using less power. By being billed differently for the same power.

Plan	Per year	Vs best
Residential Heating Service - Rate 39The hour never matters here — only the season. Rates peak June–September.	$1,455	—
R (Residential Service) - Rate 1The hour never matters here — only the season. Rates peak June–September.	$1,681	+$226
Residential Heating Service TOU - Rate 39Peak hits noon–6pm every day, all year.	$1,859	+$404

An estimate, not a quote. Supply charges move month to month, and your real usage pattern is not exactly this one. What it does show reliably is the gap between plans — both are priced off the same assumptions.

Before you switch anything

Every plan, in detail

Hour-by-hour schedules, tier thresholds, and the tariff each one comes from.