Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Details 2)

v2.4.1.9
Summary of Significant Accounting Policies (Details 2) (USD $)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Summary Of Significant Accounting Policies [Line Items]    
Beginning balance   $ 6,277,000us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Ending balance 0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue 6,277,000us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Convertible Notes Payable [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Derivative Fair Value Of Derivative Net (26,790,177)us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember 		 
Convertible Debt Securities [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Derivative Fair Value Of Derivative Net 26,265,177us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_ConvertibleDebtSecuritiesMember 		 
Financing Warrant [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Derivative Fair Value Of Derivative Net (1,733,000)us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_FinancingWarrantMember 		 
Consulting Warrant [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Derivative Fair Value Of Derivative Net $ (4,019,000)us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConsultingWarrantMember