How Much Can Solar Reduce Monthly Electricity Costs?
Solar may reduce a meaningful portion of monthly electricity costs, but the result depends on system capacity, daytime consumption, tariff structure, roof conditions, solar generation, self-consumption and the treatment of excess electricity.
How Much Can Solar Typically Reduce a Monthly Electricity Bill?
For a property with a suitable roof and consistent daytime consumption, solar may reduce the electricity-cost portion of the monthly bill by roughly 30% to 70%. Some properties may achieve a higher reduction, while others may achieve less.
Lower Daytime Usage
A property that is mostly empty during the day may use less solar electricity directly and may experience a more modest bill reduction.
Moderate Daytime Usage
Regular daytime use from appliances, air conditioning, offices or business operations can improve solar self-consumption.
High Daytime Usage
Factories, shops, offices and occupied homes with strong daytime loads may use a larger share of solar generation directly.
Night-Heavy Usage
Properties using most electricity after sunset may have lower direct solar savings unless consumption is shifted or storage is added.
How Are Monthly Solar Savings Calculated?
A solar savings estimate usually begins with the electricity generated by the system and then determines how much of that electricity is used directly by the property.
Review Electricity Use
Examine monthly consumption, bill value and, where available, time-based load data.
Estimate Solar Generation
Model the expected monthly and annual output of the proposed system.
Match Solar to Load
Estimate how much solar electricity will be consumed while it is being generated.
Value Direct Consumption
Apply the relevant avoided electricity cost to solar used directly.
Value Excess Electricity
Apply the applicable treatment or value to electricity not used immediately.
Subtract Remaining Charges
Account for nighttime consumption and bill components that solar does not remove.
Illustrative Monthly Electricity-Bill Reduction Examples
The examples below are simplified illustrations only. Actual savings depend on system design, tariff, usage pattern, generation and project rules.
| Monthly Bill Before Solar | Illustrative Reduction | Possible Monthly Saving | Illustrative Remaining Bill |
|---|---|---|---|
| RM200 | 30%–50% | Approximately RM60–RM100 | Approximately RM100–RM140 |
| RM400 | 35%–60% | Approximately RM140–RM240 | Approximately RM160–RM260 |
| RM700 | 40%–65% | Approximately RM280–RM455 | Approximately RM245–RM420 |
| RM1,000 | 40%–70% | Approximately RM400–RM700 | Approximately RM300–RM600 |
| RM5,000 Commercial Bill | 30%–65% | Approximately RM1,500–RM3,250 | Approximately RM1,750–RM3,500 |
Why Is Solar Self-Consumption Important?
Self-consumption is the percentage of solar electricity used directly by the property while the system is generating power.
| Solar Energy Category | Meaning | Effect on Savings |
|---|---|---|
| Direct Self-Consumption | Solar electricity is used immediately by appliances, equipment or building loads. | Usually creates direct savings by reducing electricity purchased from the grid. |
| Excess Solar Electricity | Solar generation is greater than the property’s immediate load. | Its value depends on the applicable export or energy arrangement. |
| Curtailed Electricity | Potential solar production is intentionally limited or unused. | Produces less financial value than electricity used directly. |
| Battery Charging | Excess solar is stored for later consumption. | May increase later solar use but introduces battery cost and efficiency losses. |
How Does Daytime Electricity Usage Affect Solar Savings?
Solar panels generate most of their electricity during daylight hours. Properties using more electricity during that period can normally consume more solar electricity directly.
Loads that may be shifted into solar hours include:
- Washing machines
- Clothes dryers
- Dishwashers
- Water heaters
- Pool pumps
- EV charging
- Air-conditioning pre-cooling
- Industrial pumping
- Cold-room operation
- Battery charging
How Does Solar System Size Affect Monthly Bill Reduction?
A larger solar system can generate more electricity, but it does not automatically produce a proportionally larger bill reduction.
Undersized System
A small system may have high self-consumption but leave a large part of the electricity bill unchanged.
Well-Matched System
A system aligned with daytime demand may balance generation, self-consumption and project cost.
Roof-Maximised System
Filling the available roof may increase total generation but can also produce more excess electricity.
Oversized System
A system much larger than daytime demand may have a lower direct-use percentage and weaker savings assumptions.
How Does Solar Generation Affect Monthly Savings?
Monthly solar output changes with weather, shading, system design, temperature, equipment performance and maintenance condition.
- Installed system capacity
- Panel orientation
- Panel tilt
- Roof shading
- Cloud cover
- Rainy periods
- Panel temperature
- Dust and dirt
- Inverter efficiency
- Cable losses
- Equipment availability
- Long-term panel degradation
How Does Excess Solar Electricity Affect Savings?
When the solar system produces more electricity than the property is using at that moment, the excess may be exported, stored, curtailed or otherwise managed according to the applicable project arrangement.
| Excess-Energy Treatment | Possible Benefit | Important Question |
|---|---|---|
| Export to Grid | Excess electricity may receive an applicable credit or value. | What rate, limit, period and eligibility conditions apply? |
| Battery Storage | Electricity may be used later instead of being exported. | Does the additional saving justify the battery cost? |
| Load Shifting | Appliances or equipment may be operated during solar hours. | Which loads can be shifted without affecting operations? |
| Generation Curtailment | Output is limited when it cannot be used or exported. | How much estimated annual production may be curtailed? |
Can a Solar Battery Increase Monthly Electricity Savings?
A battery may increase the percentage of solar electricity used by the property, especially where evening or nighttime consumption is high. However, the additional savings must be compared with battery cost, efficiency losses, warranty and replacement risk.
Why Might the Electricity Bill Not Reach Zero?
Even a large solar system may not eliminate every monthly electricity charge.
- Nighttime electricity consumption
- Rainy or cloudy periods
- Fixed account charges
- Minimum bill requirements
- Taxes or levies
- Demand-related charges
- Power-factor-related charges
- Metering charges
- System downtime
- Excess load beyond solar generation
- Battery charging losses
- Export-value differences
What Should a Solar Savings Proposal Include?
- Current monthly electricity consumption
- Current monthly bill value
- Tariff assumptions
- Proposed solar capacity in kWp
- Estimated monthly solar generation
- Estimated annual solar generation
- Estimated direct self-consumption
- Estimated excess electricity
- Estimated curtailment
- Estimated battery charging, if applicable
- Estimated monthly saving
- Estimated annual saving
- Remaining grid consumption
- Remaining bill charges
- Weather assumptions
- Shading assumptions
- System-loss assumptions
- Panel degradation
- Electricity-price assumptions
- Maintenance-cost assumptions
- Financing-cost assumptions
- Performance exclusions
How Should Solar Savings Estimates Be Compared?
| Comparison Item | Why It Matters | Question to Ask |
|---|---|---|
| System Capacity | A larger system may naturally show higher total generation. | Are both quotations based on the same kWp capacity? |
| Generation Estimate | Higher projected output produces higher projected savings. | What annual yield and system losses were assumed? |
| Self-Consumption Rate | Direct use often has a strong effect on financial savings. | Is the estimate based on actual daytime load data? |
| Electricity-Rate Assumption | A higher avoided rate creates a larger savings estimate. | Which tariff or bill components were used? |
| Export Assumption | Excess-energy treatment can materially affect value. | What value was assigned to exported electricity? |
| Future Price Growth | Aggressive escalation assumptions can make long-term savings appear larger. | What annual electricity-price increase was assumed? |
What Is the Difference Between Solar100 and a Solar Provider?
| Solar100 | Solar Provider or Installer |
|---|---|
| Provides general solar-savings guidance | Reviews the customer’s actual bills and electricity profile |
| Explains common factors affecting bill reduction | Designs the proposed system and estimates generation |
| Helps users compare participating providers | Calculates project-specific self-consumption and savings |
| Highlights assumptions, exclusions and remaining charges | Prepares the detailed technical and financial proposal |
| Does not issue engineering designs or guaranteed savings | Provides projections and commitments according to contract scope |
| Does not install or operate the solar system | Installs, commissions and supports the system according to scope |
What Information Is Needed to Estimate Monthly Solar Savings?
- Property location
- Property type
- Recent electricity bills
- At least 12 months of usage data
- Monthly kWh consumption
- Current tariff category
- Daytime occupancy or operating hours
- Weekend operating pattern
- Major daytime electrical loads
- Nighttime electrical loads
- Interval data, if available
- Roof type
- Usable roof area
- Roof shading
- Future EV charging plans
- Future air-conditioning additions
- Future production or business expansion
- Interest in battery storage
Frequently Asked Questions
Can solar reduce an electricity bill by 50%?
It may be possible where the system is appropriately sized and the property has sufficient daytime electricity consumption. Actual results depend on generation, tariff and self-consumption.
Can solar eliminate the entire monthly electricity bill?
Not necessarily. Nighttime consumption, fixed charges, minimum charges, taxes and other bill components may remain.
Why does daytime electricity usage matter?
Solar is generated during daylight hours. Electricity used at the same time can directly reduce grid purchases.
Does a bigger solar system always create more savings?
It may generate more electricity, but excess generation may have a different value from electricity used directly. Oversizing can weaken the savings assumptions.
Can a battery reduce the electricity bill further?
A battery may allow more solar electricity to be used later, but its additional cost, efficiency losses and replacement risk should also be considered.
Why do solar savings estimates differ between providers?
Providers may use different generation, self-consumption, tariff, export, degradation and future electricity-price assumptions.
Estimate How Much Solar Could Reduce Your Electricity Bill
Send your latest electricity bill, property location, operating hours and roof information to compare suitable solar savings estimates from participating providers.
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